rc: new bash alias and kakoune changes

.config/kak/kakrc

@@ -9,6 +9,9 @@ set-option global makecmd 'bash build.sh'
 map global user n :make-next-error<ret>
 map global user p :make-previous-error<ret>
 
+# Toggle line comments for the current selection/line.
+map global user / ': comment-line<ret>'
+
 # Kakoune does not have a Vim-style 'expandtab' option. Make a literal Tab key
 # insert four spaces instead of a tab character while in insert mode.
 map global insert <tab> '<space><space><space><space>'