feature: create menhir filetype for mly files

Author: undu

README.md

@@ -16,8 +16,9 @@ Plugin 'ocaml/vim-ocaml'
 NeoBundleInstall ocaml/vim-ocaml'
 
 " or use NeoBundleLazy
-NeoBundleLazy 'rgrinberg/vim-ocaml', {'autoload' : {'filetypes' :
-    \ ['ocaml', 'ocamlinterface', 'ocamllex', 'dune', 'opam', 'oasis', 'omake', 'ocamlbuild_tags', 'sexplib']}}
+NeoBundleLazy 'ocaml/vim-ocaml', {'autoload' : {'filetypes' : [
+    \ 'ocaml', 'ocamlinterface', 'ocamllex', 'menhir', 'dune', 'opam',
+    \ 'oasis', 'omake', 'ocamlbuild_tags', 'sexplib']}}
 ```
 
 ## History

ftdetect/menhir.vim

@@ -0,0 +1 @@
+au BufNewFile,BufRead *.mly setf menhir

ftdetect/ocaml.vim

@@ -1 +1 @@
-au BufNewFile,BufRead *.ml,*.mly,.ocamlinit,*.mlt,*.mlp,*.ml.cppo setf ocaml
+au BufNewFile,BufRead *.ml,.ocamlinit,*.mlt,*.mlp,*.ml.cppo setf ocaml

ftplugin/menhir.vim

@@ -0,0 +1,12 @@
+" Language:    Menhir
+" Maintainer:  vim-ocaml maintainers
+" URL:         http://www.github.com/ocaml/vim-ocaml
+
+if exists("b:did_ftplugin")
+  finish
+endif
+
+runtime! ftplugin/ocaml.vim
+runtime! ftplugin/ocaml_*.vim ftplugin/ocaml/*.vim
+
+" vim:sw=2 fdm=indent