add Help command

[32Puschel]

Sometimes you just forget stuff, like the just commands.

My idea would be to add "just help" which would then list the commands as described here.

Also,
Thank you to everyone that contributes to this project!

[spantaleev]

Running just just already prints some help. It currently looks like this:

Available recipes:
    default                             # Shows help
    install-all *extra_args             # Runs the playbook with --tags=install-all,ensure-matrix-users-created,start and optional arguments
    install-service service *extra_args # Runs installation tasks for a single service
    lint                                # Runs ansible-lint against all roles in the playbook
    rebuild-mautrix-meta-instagram      # Rebuilds the mautrix-meta-instagram Ansible role using the mautrix-meta-messenger role as a source
    register-user username password admin_yes_or_no *extra_args # Runs the playbook in user-registration mode
    roles                               # Pulls external Ansible roles
    run +extra_args                     # Runs the playbook with the given list of arguments
    run-tags tags *extra_args           # Runs the playbook with the given list of comma-separated tags and optional arguments
    setup-all *extra_args               # Runs the playbook with --tags=setup-all,ensure-matrix-users-created,start and optional arguments
    start-all *extra_args               # Starts all services
    start-group group *extra_args       # Starts a specific service group
    stop-all *extra_args                # Stops all services
    stop-group group *extra_args        # Stops a specific service group
    update *flags                       # Updates the playbook and installs the necessary Ansible roles pinned in requirements.yml. If a -u flag is passed, also updates the requirements.yml file with new role versions (if available)
    update-playbook-only                # Updates the playbook without installing/updating Ansible roles

This is quite helpful already for reminding you about the available recipes and how they're to be invoked, but docs/just.md contains a few extra details, I guess.