Neighbor letters for combinations

[Gunyon]

Hi
It would be more practical and efficient if the 2 letter combinations would consist of letters that are neighbor to each other

If anyone is interested in proposing a solution in my fork please consider creating a PR.

I linked to the file that currently creates a codes which take an input abc for example, and produce the codes based on the distance of the input characters.

// `abc` output
[
  'aa', 'ab', 'ba',
  'ac', 'bb', 'ca',
  'bc', 'cb', 'cc'
]

[wenfangdu]

@Gunyon Jump allows you to adjust the primary charset, the first specified letters will occur the closest to the last cursor position.