docs(functions): clarify function invocation instructions and improve…

… code examples in custom functions documentation

src/pages/[platform]/build-a-backend/functions/custom-functions/index.mdx

@@ -110,15 +110,15 @@ You're now ready to deploy your python function. Next is the same process as the
 To get started, Create a new directory and a resource file, `amplify/functions/say-hello/resource.ts`. Then, define the function with `defineFunction`:  
 
 ```ts title="amplify/functions/say-hello/resource.ts"
-import { defineFunction } from "@aws-amplify/backend";
-import { DockerImage, Duration } from "aws-cdk-lib";
-import { Code, Function, Runtime } from "aws-cdk-lib/aws-lambda";
 import { execSync } from "node:child_process";
 import * as path from "node:path";
 import { fileURLToPath } from "node:url";
 import { defineFunction } from "@aws-amplify/backend";
 import { DockerImage, Duration } from "aws-cdk-lib";
 import { Code, Function, Runtime } from "aws-cdk-lib/aws-lambda";
+import { defineFunction } from "@aws-amplify/backend";
+import { DockerImage, Duration } from "aws-cdk-lib";
+import { Code, Function, Runtime } from "aws-cdk-lib/aws-lambda";
 export const sayHelloFunctionHandler = defineFunction(
   (scope) =>
     new Function(scope, "say-hello", {
@@ -193,6 +193,7 @@ You're now ready to deploy your golang function. Next is the same process as the
 ## Common steps for all languages  
 
 Regardless of the language used, your function needs to be added to your backend.
+```ts title="amplify/backend.ts"
 // highlight-next-line
 import { sayHelloFunctionHandler } from './functions/say-hello/resource';
 
@@ -204,10 +205,9 @@ defineBackend({
 
 Now when you run `npx ampx sandbox` or deploy your app on Amplify, it will include your Function.
 
-To invoke your Function, we recommend adding your [Function as a handler for a custom query with your Amplify Data resource](/[platform]/build-a-backend/data/custom-business-logic/). This will enable you to strongly type Function arguments and the return statement, and use this to author your Function's business logic. To get started, open your `amplify/data/resource.ts` file and specify a new query in your schema:
+To invoke your function, we recommend adding your [function as a handler for a custom query with your Amplify Data resource](/[platform]/build-a-backend/data/custom-business-logic/). To get started, open your `amplify/data/resource.ts` file and specify a new query in your schema:
 
 ```ts title="amplify/data/resource.ts"
-Now when you run `npx ampx sandbox` or deploy your app on Amplify, it will include your function.
 import { sayHelloFunctionHandler } from "../functions/say-hello/resource"
 
 const schema = a.schema({