feat(perf): Requests module SDK instrumentation documentation (#9963)

* Link to custom instrumentation docs
* Add JavaScript platform docs
* Add Python platform docs

---------

Co-authored-by: Liza Mock <liza.mock@sentry.io>

docs/platforms/javascript/common/performance/instrumentation/requests-module.mdx

@@ -0,0 +1,51 @@
+---
+title: Custom Instrumentation for Requests Module
+sidebar_order: 9999
+description: "Learn how to manually instrument your code to use Sentry's Requests module."
+---
+
+As a prerequisite to setting up [Requests](/product/performance/requests/), you’ll need to first <PlatformLink to="/performance/">set up performance monitoring</PlatformLink>. Once this is done, the JavaScript SDK will automatically instrument outgoing HTTP requests. If that doesn't fit your use case, you can set up using [custom instrumentation](#custom-instrumentation).
+
+## Custom Instrumentation
+
+For detailed information about which data can be set, see the [Requests Module developer specifications](https://develop.sentry.dev/sdk/performance/modules/requests/).
+
+### Initialize Sentry
+
+<PlatformContent includePath="getting-started-config" />
+
+### Wrap The HTTP Requests in a Span
+
+NOTE: Refer to [HTTP Span Data Conventions](https://develop.sentry.dev/sdk/performance/span-data-conventions/#http) for a full list of the span data attributes.
+
+Here is an example of an instrumented function that makes HTTP requests:
+
+```javascript
+async function makeRequest(method, url) {
+  return await Sentry.startSpan(
+    {op: 'http.client', name: `${method} ${url}`},
+    async span => {
+      const parsedURL = new URL(url, location.origin);
+
+      const response = await fetch(url, {
+        method,
+      });
+
+      span?.setAttribute('http.request.method', method);
+
+      span?.setAttribute('server.address', parsedURL.hostname);
+      span?.setAttribute('server.port', parsedURL.port || undefined);
+
+      span?.setAttribute('http.response.status_code', response.status);
+      span?.setAttribute(
+        'http.response_content_length',
+        Number(response.headers.get('content-length'))
+      );
+
+      // A good place to set other span attributes
+
+      return response;
+    }
+  );
+}
+```

docs/platforms/python/performance/instrumentation/requests-module.mdx

@@ -0,0 +1,49 @@
+---
+title: Custom Instrumentation for Requests Module
+sidebar_order: 9999
+description: "Learn how to manually instrument your code to use Sentry's Requests module."
+---
+
+As a prerequisite to setting up [Requests](/product/performance/requests/), you’ll need to first <PlatformLink to="/performance/">set up performance monitoring</PlatformLink>. Once this is done, the Python SDK will automatically instrument outgoing HTTP requests made via `HTTPConnection`. If that doesn't fit your use case, you can set up using [custom instrumentation](#custom-instrumentation).
+
+## Custom Instrumentation
+
+For detailed information about which data can be set, see the [Requests Module developer specifications](https://develop.sentry.dev/sdk/performance/modules/requests/).
+
+### Initialize Sentry
+
+<PlatformContent includePath="getting-started-config" />
+
+### Wrap The HTTP Requests in a Span
+
+NOTE: Refer to [HTTP Span Data Conventions](https://develop.sentry.dev/sdk/performance/span-data-conventions/#http) for a full list of the span data attributes.
+
+Here is an example of an instrumented function that makes HTTP requests:
+
+```python
+from urllib.parse import urlparse
+import requests
+
+def make_request(method, url):
+    span = sentry_sdk.start_span(
+        op="http.client",
+        description="%s %s" % (method, url),
+    )
+
+    span.set_data("http.request.method", method)
+
+    parsed_url = urlparse(url)
+    span.set_data("url", url)
+    span.set_data("server.address", parsed_url.hostname)
+    span.set_data("server.port", parsed_url.port)
+
+    response = requests.request(method=method, url=url)
+
+    span.set_data("http.response.status_code", response.status_code)
+    span.set_data("http.response_content_length", response.headers["content-length"])
+
+    span.finish()
+
+    return response
+
+```

docs/product/performance/requests.mdx

@@ -21,24 +21,15 @@ On the [**Requests** page](#requests-page), you get an overview of the domains t
   ></iframe>
 </div>
 
-## Prerequisites
+## Prerequisites and Limitations
 
 <Note>
 Network requests using non-HTTP protocols (FTP, WebSocket, etc.) are not supported at this time.
 </Note>
 
 Availability of HTTP request monitoring depends on the SDK your application uses. In most cases, Sentry's SDKs automatically enable HTTP request tracking. You can check your SDK's <PlatformLink to="/performance/instrumentation/automatic-instrumentation">automatic instrumentation documentation</PlatformLink> to see if it includes tracking HTTP requests.
 
-### Span Eligibility
-
-If the SDK you are using doesn't automatically instrument HTTP requests, you can use <PlatformLink to="/performance/instrumentation/custom-instrumentation/">custom instrumentation</PlatformLink>. For best results, follow these guidelines for your custom spans:
-
-- The `op` field is set to `"http.client"`.
-- The `description` field contains the HTTP method and the full URL of the request (e.g., `"GET http://my.service.io/some-data"`).
-- If the request is to a relative URL (e.g., `"GET /data.json"`), the `server.address` span data value should be set to the server address (e.g., `"my.service.io"`).
-- The `http.response.status_code` contains the HTTP response status code (e.g., `"200"`).
-
-See the [Span Data Conventions](https://develop.sentry.dev/sdk/performance/span-data-conventions/#http) page for more information.
+If the SDK you're using doesn't automatically instrument HTTP requests, you can instrument your application by following the <PlatformLink to="/performance/instrumentation/requests-module/">custom instrumentation</PlatformLink> instructions. Because all the concepts are the same, if your platform doesn't have dedicated custom instrumentation instructions, you can try adapting the code from another platform.
 
 ## Requests Page