add compat_flag changelog for http servers (#24923)

Author: anonrig

src/content/compatibility-flags/enable-nodejs-http-server-modules.md

@@ -0,0 +1,33 @@
+---
+_build:
+  publishResources: false
+  render: never
+  list: never
+
+name: "Enable Node.js HTTP server modules"
+sort_date: "2025-09-01"
+enable_date: "2025-09-01"
+enable_flag: "enable_nodejs_http_server_modules"
+disable_flag: "disable_nodejs_http_server_modules"
+---
+
+The `enable_nodejs_http_server_modules` flag enables the availability of Node.js
+HTTP server modules such as `node:_http_server` in Workers.
+
+The `disable_nodejs_http_server_modules` flag disables the availability of these
+server modules.
+
+This enables compatibility with Node.js libraries and existing code that
+use the standard Node.js HTTP server APIs. The available functionality includes:
+
+* `http.createServer()` for creating HTTP servers
+* `http.Server` class for server instances
+* `http.ServerResponse` for handling server responses
+
+This flag must be used in combination with the `enable_nodejs_http_modules` flag
+to enable full features of `node:http`.
+
+This flag is automatically enabled for Workers using
+a compatibility date of 2025-09-01 or later when `nodejs_compat` is enabled.
+
+See the [Node.js documentation](https://nodejs.org/docs/latest/api/http.html) for more details about the Node.js HTTP APIs.