vim-patch:9.1.0961: filetype: TI gel files are not recognized

Problem:  filetype: TI gel files are not recognized
Solution: detect '*.gel' files as gel filetype, include
          get filetype and syntax plugins
          (Wu, Zhenyu)

References:
https://downloads.ti.com/ccs/esd/documents/users_guide/ccs_debug-gel.html

closes: vim/vim#16226

9360de9027

Co-authored-by: Wu, Zhenyu <wuzhenyu@ustc.edu>

runtime/lua/vim/filetype.lua

@@ -504,6 +504,7 @@ local extension = {
   gdshader = 'gdshader',
   shader = 'gdshader',
   ged = 'gedcom',
+  gel = 'gel',
   gmi = 'gemtext',
   gemini = 'gemtext',
   gift = 'gift',