Add Usage block to RequestHandler

Author: snejus

beetsplug/_utils/requests.py

@@ -92,6 +92,17 @@ class RequestHandler:
     conversion of standard HTTP errors to beets-specific exceptions. Supports
     custom session types and error mappings that can be overridden by
     subclasses.
+
+    Usage:
+        Subclass and override :class:`RequestHandler.session_type`,
+        :class:`RequestHandler.explicit_http_errors` or
+        :class:`RequestHandler.status_to_error()` to customize behavior.
+
+        Use :class:`RequestHandler.get()` or
+        :class:`RequestHandler.fetch_json()` for common operations, or
+        :class:`RequestHandler.request()` for full control over HTTP methods.
+
+        Feel free to define common methods that are used in multiple plugins.
     """
 
     session_type: ClassVar[type[TimeoutSession]] = TimeoutSession