vim-patch:9.1.0386: filetype: stylus files not recognized

Problem:  filetype: stylus files not recognized
Solution: Detect '*.styl' and '*.stylus' as stylus filetype,
          include indent, filetype and syntax plugin
          (Philip H)

closes: vim/vim#14656

2d919d2744

Co-authored-by: Philip H <47042125+pheiduck@users.noreply.github.com>

runtime/lua/vim/filetype.lua

@@ -1015,6 +1015,8 @@ local extension = {
   mata = 'stata',
   ado = 'stata',
   stp = 'stp',
+  styl = 'stylus',
+  stylus = 'stylus',
   quark = 'supercollider',
   sface = 'surface',
   svelte = 'svelte',