support readline in some window (e.g., Edit preference)

[Freed-Wu]

Is your feature request related to a problem? Please describe. A clear and concise description of what the problem is. Ex. I'm always frustrated when [...] In some window (e.g, Edit preference), if support readline: <C-B>, <C-F>, <C-P>, <C-N> to go left, right, up, down, it will be more convenient.

Describe alternatives you've considered Perhaps hjkl?

[inducer]

I think all that's needed here is to switch more edit fields to urwid_readline.ReadlineEdit. PRs welcome.