added more info for user to generate app passaword (#271)

* Add Gmail MCP Server for email operations

- Supports listing messages, searching emails, and sending messages
- Uses IMAP/SMTP with app password authentication
- Includes proper tools.json for build process
- Pre-built Docker image: yashtekwani/gmail-mcp:latest

* added info for users to create app password

Author: Sallytion

servers/gmail-mcp/server.yaml

@@ -11,7 +11,7 @@ meta:
     - communication
 about:
   title: Gmail MCP Server
-  description: A Model Context Protocol server for Gmail operations using IMAP/SMTP with app password authentication. Supports listing messages, searching emails, and sending messages.
+  description: A Model Context Protocol server for Gmail operations using IMAP/SMTP with app password authentication. Supports listing messages, searching emails, and sending messages. To create your app password, visit your Google Account settings under Security > App Passwords. Or visit the link https://myaccount.google.com/apppasswords
   icon: https://www.google.com/gmail/about/static/images/logo-gmail.png
 source:
   project: https://github.com/Sallytion/Gmail-MCP