bash completion should just work when you install new commands. Bash::Completion
is a system to use and write bash completion rules.

For end-users, you just need to add this line to your .bashrc or .bash_profile:

    setup-bash-complete

This will load all the installed Bash::Completion plugins, make sure they should
be activated and generate the proper bash code to setup bash completion for
them.

If you later install a new command line tool, and it has a
Bash::Completion::Plugin -based plugin, all your new shells will have bash
completion rules for it. You can also force immediate setup by running the same
command:

    setup-bash-complete

To write a new Bash::Completion plugin, see Bash::Completion::Plugin.