[AllAboutDocs]

What

Adds a CLI reference page (docs/CLI.md) documenting the two available commands, mkdocs build and mkdocs serve, including their options. Also adds a link to this new page from the "Getting started" section of the homepage (docs/README.md), since it's the section that already introduces both commands by name.

Why

Following up on the CLI documentation topic flagged after #60 - there's currently no reference page for the command-line tool itself, just a couple of commands mentioned in passing.

Notes

• Documents --dir/--output on build and --dir on serve, all tested directly (not just taken from --help text).
• Includes a note on the known mkdocs build console-output issue (Build output should list build outputs, not source inputs. #61), since it's the first thing most users will see.
• Includes a note that serve does not currently support live-reload - confirmed by editing a file while the server was running and observing no auto-refresh.

Testing

Ran mkdocs serve locally and confirmed:

• The CLI page renders correctly at /cli/ - headings, code blocks, and both notes all display as expected.
• The new "CLI Reference" link on the homepage navigates correctly to the page.
• The --dir and --output flags on build behave as documented (tested with a throwaway source/output folder).