feat(ft): add autohotkey support (#303)

https://www.autohotkey.com/docs/v1/Language.htm#comments
https://www.autohotkey.com/docs/v2/Language.htm#comments

NOTE: autohotkey restricts the end tag to appearing at the start
of a line, or in v2 at the end of a line. With those restrictions, it
may be better to only define the line comment.

Author: mgziminsky

lua/Comment/ft.lua

@@ -38,6 +38,7 @@ local M = {
 local L = setmetatable({
     arduino = { M.cxx_l, M.cxx_b },
     applescript = { M.hash },
+    autohotkey = { ";%s", M.cxx_b },
     bash = { M.hash },
     bib = { M.latex },
     c = { M.cxx_l, M.cxx_b },