[Feature] Add mappings for easier movement.

[filipdutescu]

Describe the issue

There is no way to select the buffer contents or to move easier and faster than 1 letter at a time.

Proposal

Define key mappings to have better movement inside the renamer.nvim popup buffer and window.

Alternatives

Start with the <cword> selected. This might still be a good idea, but key mappings are more important, in my opinion.

Additional context