Fix remaining broken links

Author: catplat

sites/platform/src/create-apps/app-reference/_index.md

@@ -38,7 +38,7 @@ Manually defining a stack in a composable image is typically simpler than adding
 
 Consider using a composable image when these factors are important:
 - Your application requires multiple runtimes and tools, or different versions of the same package.
-- You build your own services. See the [Building your own services](#building-services) section below.
+- You build your own services. 
 - You want the ability to install _all_ the packages you need in your application container, ensuring that an application works on any machine.<BR> 
     In a composable image, you can accomplish this by using supported Nix channels. This method ensures app consistency and helps to streamline the development, testing, and deployment processes.
 
@@ -62,7 +62,7 @@ Consider using a composable image when these factors are important:
 
 ## Keys used in each image type
 
-Only the single-runtime image supports the [``build``](/create-apps/app-reference/single-runtime-image.md#build), [``dependencies``](/create-apps/app-reference/single-runtime-image.md#dependencies), and [``runtime``](/create-apps/app-reference/single-runtime-image.md#druntime) keys. In a composable image, the equivalent is the [`stack`](/create-apps/app-reference/composable-image.md#stack) key. 
+Only the single-runtime image supports the [``build``](/create-apps/app-reference/single-runtime-image.md#build), [``dependencies``](/create-apps/app-reference/single-runtime-image.md#dependencies), and [``runtime``](/create-apps/app-reference/single-runtime-image.md#runtime) keys. In a composable image, the equivalent is the [`stack`](/create-apps/app-reference/composable-image.md#stack) key. 
 
 Otherwise, the same keys are available for both image types. Differences in syntax or meaning are noted in each key's topic - see the [Image properties](/create-apps/image-properties.md) section for the topics that describe each key.  
 

sites/platform/src/create-apps/app-reference/single-runtime-image.md

@@ -212,3 +212,36 @@ The following table shows the properties that can be set in `sizing_hints`:
 | `reserved_memory` | `integer` | 70      | 70      | The amount of memory reserved in MB.           |
 
 See more about [PHP-FPM workers and sizing](/languages/php/fpm.md).
+
+## Combine single-runtime and composable images {#combine-single-runtime-and-composable-images}
+
+In a [multiple application context](/create-apps/multi-app/_index.md),
+you can use a mix of single-runtime images and [composable images](/create-apps/app-reference/composable-image.md).
+
+
+The following sample configuration includes two applications:
+- ``frontend`` – uses a single-runtime image
+- ``backend`` – uses a composable image<br>
+  In this app, PHP is the primary runtime and is started automatically (PHP-FPM also starts automatically when PHP is the primary runtime). For details, see the [PHP as a primary runtime](#php-as-a-primary-runtime) section in this topic.
+
+
+```yaml {configFile="app"}
+applications:
+  frontend:
+    # this app uses the single-runtime image with a specific node.js runtime
+    type: 'nodejs:{{% latest "nodejs" %}}'
+  backend:
+    # this app uses the composable image and specifies two runtimes
+    type: "composable:8.4"
+    stack:
+      runtimes:
+        - "[email protected]":
+            extensions:
+              - apcu
+              - sodium
+              - xsl
+              - pdo_sqlite
+        - "[email protected]"
+      packages:
+        - "python313Packages.yq" # python package specific
+```

sites/platform/src/create-apps/image-properties/crons.md

@@ -86,7 +86,7 @@ applications:
 
 {{< /codetabs >}}
 
-In this example configuration, the crons [`spec`](#crons) uses the `H` syntax.
+In this example configuration, the crons `spec` key uses the `H` syntax.
 
 Note that this syntax is only supported on Grid projects.
 On {{% names/dedicated-gen-2 %}} projects, use the [standard cron syntax](https://en.wikipedia.org/wiki/Cron#Cron_expression).

sites/platform/src/create-apps/image-properties/disk.md

@@ -10,7 +10,7 @@ Optional in [single-runtime](/create-apps/app-reference/single-runtime-image.md#
 
 The maximum total space available to all apps and services is set by the storage in your plan settings.
 When deploying your project, the sum of all `disk` keys defined in app and service configurations
-must be *equal or less* than the plan storage size.
+cannot exceed the available storage in your plan.
 
 So if your *plan storage size* is 5 GB, you can, for example, assign it in one of the following ways:
 
@@ -23,7 +23,10 @@ You need to either increase your plan's storage or decrease the `disk` values yo
 
 You configure the disk size in [MB](/glossary/_index.md#mb). Your actual available disk space is slightly smaller with some space used for formatting and the filesystem journal. When checking available space, note whether it’s reported in MB or MiB.
 
-### Altering `disk` values
+If you need more storage to fit the sum of all `disk` keys, it is necessary to [switch plans](/administration/pricing.md#switch-plans). This can only be done by people with the [manage plans permission](/administration/users.md#organization-permissions).
+
+
+### Backups and altering `disk` values
 
 It's a best practice to [back up your environment](/environments/backup.md) **before and after** you increase **or** decrease the `disk` value (the amount of allocated storage space) of an app or service.
 

sites/platform/src/create-apps/image-properties/workers.md

@@ -57,7 +57,7 @@ title=Composable image
 
 The keys of the `workers` definition are the names of the workers.
 You can then define how each worker differs from the `web` instance using
-the [top-level properties](#primary-application-properties).
+the [top-level properties](/create-apps/app-reference/composable-image.md#primary-application-properties).
 
 Each worker can differ from the `web` instance in all properties _except_ for:
 

sites/platform/src/create-apps/troubleshoot-disks.md

@@ -23,7 +23,7 @@ Error: Resources exceeding plan limit; disk: 8192.00MB > 5120.00MB; try removing
 To fix the error, do one of the following:
 
 * Lower the `disk` parameters to a value within your plan's storage limits.
-  Note the [limits to downsizing disks](/create-apps/app-reference/single-runtime-image.md#downsize-a-disk).
+  Note the [limits to downsizing disks](/create-apps/image-properties/disk.md).
 * Increase your plan's storage limits.
   This can only be done by people with the [manage plans permission](/administration/users.md#organization-permissions).
 

sites/platform/src/languages/php/_index.md

@@ -663,9 +663,22 @@ See the example below for more details.
 | `extensions`                | List of `string`s OR [extensions definitions](/create-apps/app-reference/composable-image.md#stack) | [PHP extensions](/languages/php/extensions.md) to enable.                                               |
 | `disabled_extensions`       | List of `string`s                                                                                                                | [PHP extensions](/languages/php/extensions.md) to disable.                                              |
 | `request_terminate_timeout` | `integer`                                                                                                                        | The timeout (in seconds) for serving a single request after which the PHP-FPM worker process is killed. |
-| `sizing_hints`              | A [sizing hints definition](/create-apps/app-reference/composable-image.md#sizing-hints)                                         | The assumptions for setting the number of workers in your PHP-FPM runtime.                              |
+| `sizing_hints`              | A [sizing hints definition](#sizing-hints)                                         | The assumptions for setting the number of workers in your PHP-FPM runtime.                              |
 | `xdebug`                    | An Xdebug definition                                                                                                             | The setting to turn on [Xdebug](/languages/php/xdebug.md).                                              |
 
+### PHP-FPM service sizing hints {#sizing-hints}
+
+The following table shows the properties that can be set in `sizing_hints`:
+
+| Name              | Type      | Default | Minimum | Description                                    |
+|-------------------|-----------|---------|---------|------------------------------------------------|
+| `request_memory`  | `integer` | 45      | 10      | The average memory consumed per request in MB. |
+| `reserved_memory` | `integer` | 70      | 70      | The amount of memory reserved in MB.           |
+
+See more about [PHP-FPM workers and sizing](/languages/php/fpm.md).
+
+### Example PHP configuration {#example-php-configuration}
+
 Here is an example configuration:
 
 ```yaml {configFile="app"}

sites/upsun/src/create-apps/image-properties/crons.md

@@ -78,8 +78,7 @@ applications:
 
 {{< /codetabs >}}
 
-
-In this example configuration, the [cron specification](https://en.wikipedia.org/wiki/Cron#Cron_expression) uses the `H` syntax.
+In this example configuration, the crons `spec` key uses the `H` syntax.
 
 ### Single-runtime image: Example cron jobs