Add the xkeyboard extension to CLX

[dmb2]

I've written a long winded explanation here:
https://github.com/stumpwm/stumpwm/wiki/International-Input-and-XKeyboard-Development

In short, I want to help solve this problem in a permanent way. This will mean having CLX support the xkeyboard extension. I have opened an issue to merge clx-xkeyboard into this repo:
filonenko-mikhail/clx-xkeyboard#1

I am volunteering to coordinate the overall effort of developing XKB in CLX. I'm reaching out to see how you would like me to proceed. My nominal plan is to host a fork of sharplispers/clx, implement and test the extension, and when it is ready merge it back into sharplispers/clx.

Alternatively I'm happy to be a point of contact for coordinating contributions and individual contributions can be made as PRs directly to sharplispers/clx. Please let me know the best way to proceed.

EDIT: Changed url to an evergreen one independent of my personal github.

[dkochmanski]

sorry for this terrible response time. Pull requests here work best imo.

[dkochmanski]

if you make a PR from your specific branch on github then PR is automatically updated.