Add comment language injections (#51)

With the Comment extension installed, this will allow comments starting
with TODO, FIXME, etc to be styled

---------

Signed-off-by: Donnie Adams <donnie@thedadams.com>
Co-authored-by: MrSubidubi <dev@bahn.sh>

Author: thedadams

languages/kotlin/injections.scm

@@ -0,0 +1,5 @@
+([
+  (line_comment)
+  (multiline_comment)
+] @content
+  (#set! "language" "comment"))