docs: add "config" and "schema_cache" endpoints to the admin server

docs/references/admin_server.rst

@@ -54,3 +54,40 @@ Metrics
 =======
 
 Provides :ref:`metrics`.
+
+Runtime Configuration
+=====================
+
+Provides a ``config`` endpoint that returns the runtime :ref:`configuration`.
+
+.. code-block:: bash
+
+  curl "http://localhost:3001/config"
+
+.. code-block::
+
+  db-aggregates-enabled = false
+  db-anon-role = "web_anon"
+  db-channel = "pgrst"
+  db-channel-enabled = false
+  ...
+
+Runtime Schema Cache
+====================
+
+Provides the ``schema_cache`` endpoint that prints the runtime :ref:`schema_cache`.
+
+.. code-block:: bash
+
+  curl "http://localhost:3001/schema_cache"
+
+.. code-block:: json
+
+  {
+    "dbMediaHandlers": ["..."],
+    "dbRelationships": ["..."],
+    "dbRepresentations": ["..."],
+    "dbRoutines": ["..."],
+    "dbTables": ["..."],
+    "dbTimezones": ["..."]
+  }