Update mkdocs.yml

mkdocs.yml

@@ -78,7 +78,9 @@ nav:
       - 'Move vmail volume': 'u_e-dovecot-vmail-volume.md'
       - 'IMAP IDLE interval': 'u_e-dovecot-idle_interval.md'
       - 'FTS (Solr)': 'u_e-dovecot-fts.md'
-  - 'Nginx': 'u_e-nginx.md'
+  - 'Nginx': 
+     - "General information": 'u_e-nginx.md'
+     - "Create subdomain webmail.example.org": 'u_e-webmail-site.md'
   - 'Redis': 'u_e-redis.md'
   - 'Rspamd': 'u_e-rspamd.md'
   - 'SOGo': 'u_e-sogo.md'