Document `$kak_reg_*` changes in the changelog
Document `$kak_reg_*` changes in the changelog

Closes #2202

jkonecny12/kakoune,danr/kakoune,mawww/kakoune,danr/kakoune,occivink/kakoune,casimir/kakoune,jjthrash/kakoune,lenormf/kakoune,jjthrash/kakoune,lenormf/kakoune,occivink/kakoune,danr/kakoune,jkonecny12/kakoune,jjthrash/kakoune,lenormf/kakoune,mawww/kakoune,Somasis/kakoune,casimir/kakoune,alexherbo2/kakoune,occivink/kakoune,jkonecny12/kakoune,mawww/kakoune,occivink/kakoune,alexherbo2/kakoune,jkonecny12/kakoune,casimir/kakoune,danr/kakoune,alexherbo2/kakoune,casimir/kakoune,lenormf/kakoune,alexherbo2/kakoune,jjthrash/kakoune,Somasis/kakoune,mawww/kakoune,Somasis/kakoune,Somasis/kakoune