vim-patch:8.2.4721: cooklang files are not recognized (#18058)

Problem:    Cooklang files are not recognized.
Solution:   recognize *.cook files. (Goc Dundar, closes vim/vim#10120)
36951ed1da

runtime/lua/vim/filetype.lua

@@ -95,6 +95,7 @@ local extension = {
   clj = "clojure",
   cljc = "clojure",
   cljs = "clojure",
+  cook = "cook",
   cmake = "cmake",
   cmod = "cmod",
   lib = "cobol",