[FEATURE] support alternative sources than wikipidia (e.g. arch wiki?)

[japhir]

Is your feature request related to a problem? Please describe.

I use this tool to prevent me from opening the browser, so I can stay focused.
Sometimes I quickly want to look something up on the arch wiki.

Describe the solution you'd like
I'd like support for browsing the aw from wiki-tui somehow. Perhaps with a source flag that defaults to wikpedia?

Describe alternatives you've considered
Haven't looked yet!

Additional context

Checklist

• checked that this feature wasn't requested before in an issue
• read CONTRIBUTING.md