docs(mcp): add comprehensive Hermes MCP docs

Expand the MCP feature docs with filtering and capability-aware registration details, add a practical 'Use MCP with Hermes' tutorial, add a config reference page, and wire the new docs into the sidebar and landing page.

website/sidebars.ts

@@ -22,6 +22,7 @@ const sidebars: SidebarsConfig = {
         'guides/daily-briefing-bot',
         'guides/team-telegram-assistant',
         'guides/python-library',
+        'guides/use-mcp-with-hermes',
       ],
     },
     {
@@ -128,6 +129,7 @@ const sidebars: SidebarsConfig = {
         'reference/slash-commands',
         'reference/tools-reference',
         'reference/toolsets-reference',
+        'reference/mcp-config-reference',
         'reference/skills-catalog',
         'reference/optional-skills-catalog',
         'reference/environment-variables',