[MCP] Add documentation for how-to on MCP config JSON
Problem to solve
When a new MCP user opens the Workspace or User MCP JSON configuration file, there is not any immediate direction for how to correctly configure a new server. It would be helpful if we had documentation links and/or a sample configuration the user can use.
Proposal
With this change in the LS, feat: Add support for comments in MCP config files (gitlab-org/editor-extensions/gitlab-lsp!2153 - merged), comments are not supported in the MCP configuration files.
From this comment, I think it would be a good idea to add documentation surrounding GitLab's MCP configuration as well as an example MCP server configuration. This comment would only exist if the user has NEVER opened the MCP config file before as in that case, the extension is responsible for creating the file for the user.