patch 8.2.2392: fennel filetype not recognized

Problem:    Fennel filetype not recognized.
Solution:   Detect with pattern and hashbang. (Chinmay Dalal, closes #7729)
diff --git a/runtime/scripts.vim b/runtime/scripts.vim
index 9217b44..6448c54 100644
--- a/runtime/scripts.vim
+++ b/runtime/scripts.vim
@@ -186,6 +186,10 @@
   elseif s:name =~# 'instantfpc\>'
     set ft=pascal
 
+    " Fennel
+  elseif s:name =~# 'fennel\>'
+    set ft=fennel
+
   endif
   unlet s:name