Update README's auth block

- Add auth to TOC
- Specify python for code block highlighting
- Format auth example

Author: fcestari

README.md

@@ -30,6 +30,7 @@
     - [Prompts](#prompts)
     - [Images](#images)
     - [Context](#context)
+    - [Authentication](#authentication)
   - [Running Your Server](#running-your-server)
     - [Development Mode](#development-mode)
     - [Claude Desktop Integration](#claude-desktop-integration)
@@ -316,21 +317,29 @@ Authentication can be used by servers that want to expose tools accessing protec
 `mcp.server.auth` implements an OAuth 2.0 server interface, which servers can use by
 providing an implementation of the `OAuthServerProvider` protocol.
 
-```
-mcp = FastMCP("My App",
-        auth_provider=MyOAuthServerProvider(),
-        auth=AuthSettings(
-            issuer_url="https://myapp.com",
-            revocation_options=RevocationOptions(
-                enabled=True,
-            ),
-            client_registration_options=ClientRegistrationOptions(
-                enabled=True,
-                valid_scopes=["myscope", "myotherscope"],
-                default_scopes=["myscope"],
-            ),
-            required_scopes=["myscope"],
+```python
+from mcp.server.auth.settings import (
+    AuthSettings,
+    ClientRegistrationOptions,
+    RevocationOptions,
+)
+from mcp.server.fastmcp import FastMCP
+
+mcp = FastMCP(
+    "My App",
+    auth_provider=MyOAuthServerProvider(),
+    auth=AuthSettings(
+        issuer_url="https://myapp.com",
+        revocation_options=RevocationOptions(
+            enabled=True,
+        ),
+        client_registration_options=ClientRegistrationOptions(
+            enabled=True,
+            valid_scopes=["myscope", "myotherscope"],
+            default_scopes=["myscope"],
         ),
+        required_scopes=["myscope"],
+    ),
 )
 ```