maybe ???
https://github.com/CanonicalLtd/subiquity/blob/master/subiquitycore/core.py#L280

educational:
https://github.com/TomasTomecek/sen/blob/master/sen/tui/ui.py

check out:
https://github.com/rndusr/stig/tree/master/stig/tui

Questions:
* is it possible to make a span a urwid.Text selectable? e.g. for urls and hashtags