Document webserver configuration via ROCKET_ environment variables

Resolves #17

README.md

@@ -14,7 +14,9 @@ If you need guaranteed availability, [deploy it yourself](#deploy).
 
 You can convert markdown by sending a `POST` request to `https://md-to-pdf.fly.dev`.
 
-    curl --data-urlencode 'markdown=# Heading 1' --output md-to-pdf.pdf https://md-to-pdf.fly.dev
+```shell
+curl --data-urlencode 'markdown=# Heading 1' --output md-to-pdf.pdf https://md-to-pdf.fly.dev
+```
 
 | Parameter  | Required | Description                                                                                           |
 |------------|----------|-------------------------------------------------------------------------------------------------------|
@@ -24,14 +26,27 @@ You can convert markdown by sending a `POST` request to `https://md-to-pdf.fly.d
 
 Send data from files like this:
 
-    curl --data-urlencode "markdown=$(cat example.md)" 
+```shell
+curl --data-urlencode "markdown=$(cat example.md)" 
+```
 
 ## Deploy
 
 A prebuilt container image is available at [Docker Hub](https://hub.docker.com/r/spawnia/md-to-pdf).
+The container starts up the web service and listens for HTTP on port 8000.
+
 You can run it yourself like this:
 
-    docker run --publish=8000:8000 spawnia/md-to-pdf
+```shell
+docker run --publish=8000:8000 spawnia/md-to-pdf
+```
+
+You may configure the webserver through [Rocket environment variables](https://rocket.rs/guide/v0.5/configuration#environment-variables).
+For example, you could allow larger payloads by increasing the limit for form data:
+
+```dotenv
+ROCKET_LIMITS={form="1MiB"}
+```
 
 ## Built with
 

static/index.html

@@ -88,7 +88,9 @@ <h1 hidden="hidden">md-to-pdf</h1>
 
 You can convert markdown by sending a `POST` request to `https://md-to-pdf.fly.dev`.
 
-    curl --data-urlencode 'markdown=# Heading 1' --output md-to-pdf.pdf https://md-to-pdf.fly.dev
+```shell
+curl --data-urlencode 'markdown=# Heading 1' --output md-to-pdf.pdf https://md-to-pdf.fly.dev
+```
 
 | Parameter  | Required | Description                                                                                           |
 |------------|----------|-------------------------------------------------------------------------------------------------------|
@@ -98,14 +100,27 @@ <h1 hidden="hidden">md-to-pdf</h1>
 
 Send data from files like this:
 
-    curl --data-urlencode "markdown=$(cat example.md)"
+```shell
+curl --data-urlencode "markdown=$(cat example.md)"
+```
 
 ## Deploy
 
 A prebuilt container image is available at [Docker Hub](https://hub.docker.com/r/spawnia/md-to-pdf).
+The container starts up the web service and listens for HTTP on port 8000.
+
 You can run it yourself like this:
 
-    docker run --publish=8000:8000 spawnia/md-to-pdf
+```shell
+docker run --publish=8000:8000 spawnia/md-to-pdf
+```
+
+You may configure the webserver through [Rocket environment variables](https://rocket.rs/guide/v0.5/configuration#environment-variables).
+For example, you could allow larger payloads by increasing the limit for form data:
+
+```dotenv
+ROCKET_LIMITS={form="1MiB"}
+```
 
 ## Built with