MCP Documentation Roadmap [#3559682]

Problem/Motivation

The MCP documentation is currently hosted on an external site and is not versioned with the module’s codebase. This leads to outdated information, duplicated maintenance work, and no clear way to track documentation across releases (e.g., 1.2, 1.3, future 2.x). Moving all documentation back into the repository restores alignment, maintainability, and follows standard Drupal documentation practices.

Steps to reproduce

Visit the MCP project page and follow the “Documentation” link.
Observe that the documentation is external and does not match MCP 1.2 behavior.
Check the /docs directory and note that it contains outdated or incomplete content.

Proposed Roadmap

Move all documentation into the module repository under /docs.
Use GitLab CI to auto-generate documentation on project pages following Drupal conventions.
Update and rewrite documentation to accurately reflect MCP 1.2.
Prepare structure for version-specific documentation tied to tags and branches.
Investigate the Canvas module documentation theming and adopt similar UI improvements where appropriate.
Add visual assets (screenshots, diagrams, mascot illustrations) to improve clarity.
Create or update contribution guidelines requiring documentation changes with relevant merge requests.

Remaining tasks (each will be their own issue)

[ ] Migrate external documentation into /docs.
[ ] Audit and rewrite outdated sections.
[ ] Validate GitLab CI documentation generation pipeline.
[ ] Review Canvas module documentation implementation for reusable enhancements.
[ ] Add mascot and visual assets.
[ ] Create versioned documentation structures for 1.2 → 1.3 → future releases.
[ ] Add contributor note requiring docs updates with code changes.

User interface changes

Documentation displayed on project pages will receive updated styling, potentially borrowing navigation, layout, and theming approaches from the Canvas module. Visual improvements such as diagrams, screenshots, and mascot usage will enhance usability.