add endpoint test and update docs

Author: Anish9901

docs/docs/api/rpc.md

@@ -60,6 +60,7 @@ To use an RPC function:
     options:
       members:
       - list_
+      - delete
       - TableInfo
 
 ---

mathesar/tests/rpc/test_endpoints.py

@@ -44,6 +44,11 @@
         "tables.list",
         [user_is_authenticated]
     ),
+    (
+        tables.delete,
+        "tables.delete",
+        [user_is_authenticated]
+    )
 ]