docs: Update guide link in http package md file (angular#59955)

PR Close angular#59955

Author: kirjs

packages/common/http/PACKAGE.md

@@ -3,4 +3,4 @@ Implements an HTTP client API for Angular apps that relies on the `XMLHttpReques
 Includes testability features, typed request and response objects, request and response interception,
 observable APIs, and streamlined error handling.
 
-For usage information, see the [HTTP Client](guide/http) guide.
+For usage information, see the [HTTP Client](https://angular.dev/guide/http) guide.