Add raxol to Command Line Applications

[DROOdotFOO]

raxol is a multi-surface runtime for Elixir: one application module renders to the terminal, the browser (LiveView), SSH, and an agent surface, so the same UI code serves all four. Built on OTP, so a component that crashes is restarted by its supervisor rather than taking the application down.

Added to Command Line Applications, alphabetically after ratatouille.

Against the contribution guidelines:

• Pull request, not an issue.
• Searched first — no existing PR or issue mentions raxol.
• Hex-installable (hex.pm/packages/raxol), documented (hexdocs), tested, and compatible with current Elixir.
• Links to the source repository.
• Single suggestion in this PR, description kept short and ending with a full stop.
• Entry is alphabetically placed within its category.