feat: revamp CLI surface

[ivov]

Reshapes the lis CLI overview and tightens the command surface for first-time users.

$ lis
Lisette compiler and toolchain.

Usage:
    lis <command>

Commands:
    new        Create a new project
    build, b   Compile a project to Go
    run, r     Compile and run a project
    format, f  Format a project
    check, c   Validate a project
    doc        Browse symbols and packages

Extras:
    version    Print compiler version
    help       Show help for a command
    learn      Create a new sample project
    complete   Shell completion scripts
    lsp        Start the language server

New to Lisette? https://lisette.run/quickstart

Other changes:

• Bare lis shows overview
• lis help shows a command list
• Renames completions to complete
• Removes clean
• Adds --version alias
• lis new <name> prints cd <name> then lis run to test it.
• lis format --check distinguishes clean from dirty
• lis help <typo> suggests similar names
• lis run <missing> reports Project not found
• lis version outputs lis X.Y.Z

[github-actions]

Released in lisette-v0.1.25