Programmatical API for install/uninstall

[medikoo]

Currently, via documentation then only way to setup tabtab completion is to use tabtab.install and tabtab.unistall which initialize inquirer prompts.

It'll be great to have dedicatad programmatical functions where we can pass what type of shell we want to setup.

I've noted that technically I can refer directly to e.g. install as exported by lib/installer.js.
Still they write to the console, so also seem not perfectly isolated for programmatical usage:

tabtab/lib/installer.js

Lines 298 to 302 in 8e16e47

	console.log(`
	=> Tabtab source line added to ${location} for ${name} package.
	Make sure to reload your SHELL.
	`);