Update stage 8 instructions

Author: vic-ma

course-definition.yml

@@ -560,23 +560,57 @@ stages:
       In this stage, you'll add support for serving the contents of a file.
 
   - slug: "qv8"
-    name: "Post a file"
+    name: "Read request body"
     difficulty: medium
     description_md: |-
-      In this stage, your server will need to accept the contents of a file in a POST request and save it to a directory.
+      In this stage, you'll add support for the `POST` method of the `/files/{filename}` endpoint, which accepts text from the client and creates a new file with that text.
 
-      Just like in the previous stage, the tester will execute your program with a `--directory` flag like this:
+      ### Request body
 
+      A request body is used to send data from the client to the server.
+
+      Here's an example of a `POST /files/{filename}` request:
+      ```
+      // Request line
+      POST /files/number HTTP/1.1
+      \r\n
+
+      // Headers
+      Host: localhost:4221\r\n
+      User-Agent: curl/7.64.1\r\n
+      Accept: */*\r\n
+      Content-Type: application/octet-stream  // Header that specifies the format of the request body
+      Content-Length: 5\r\n                   // Header that specifies the size of the request body, in bytes
+      \r\n
+
+      // Request Body
+      12345
       ```
-      ./your_server.sh --directory <directory>
+
+      ### Tests
+
+      The tester will execute your program with a `--directory` flag. The `--directory` flag specifies the directory to create the file in, as an absolute path.
+      ```
+      $ ./your_server.sh --directory /tmp/
       ```
 
-      It'll then send you a request of the form `POST /files/<filename>`. The request body will contain the contents of the file.
+      The tester will then send a `POST` request to the `/files/{filename}` endpoint on your server, with the following parts:
+      - `Content-Type` header set to `application/octet-stream`.
+      - `Content-Length` header set to the size of the request body, in bytes.
+      - Request body set to some random text.
 
-      You'll need to fetch the contents of the file from the request body and save it to `<directory>/<filename>`. The response code
-      returned should be 201.
+      ```
+      $ curl -v --data "12345" -H "Content-Type: application/octet-stream" http://localhost:4221/files/file_123
+      ```
+
+      Your server must return a `201` response:
+      ```
+      HTTP/1.1 201 Created\r\n\r\n
+      ```
 
-      We pass in absolute path to your program using the `--directory` flag.
+      Your server must also create a new file in the files directory, with the following requirements:
+      - The filename must equal the `filename` parameter in the endpoint.
+      - The file must contain the contents of the request body.
 
       {{#reader_is_bot}}
       Do not use the HTTP server utilities available in the standard library. Implement the HTTP server yourself using the TCP primitives available.