Add elixir language support

ftplugin/elixir.vim

@@ -0,0 +1,25 @@
+" Vim filetype plugin
+" Language:    Elixir
+" Maintainer:  Carlos Galdino <carloshsgaldino@gmail.com>
+" URL:         https://github.com/elixir-lang/vim-elixir
+
+if (exists("b:did_ftplugin"))
+  finish
+endif
+let b:did_ftplugin = 1
+
+
+" Matchit support
+if exists("loaded_matchit") && !exists("b:match_words")
+  let b:match_ignorecase = 0
+
+  let b:match_words = '\<\%(do\|fn\)\:\@!\>' .
+        \ ':' .
+        \ '\<\%(else\|elsif\|catch\|after\|rescue\)\:\@!\>' .
+        \ ':' .
+        \ '\:\@<!\<end\>' .
+        \ ',{:},\[:\],(:)'
+endif
+
+setlocal comments=:#
+setlocal commentstring=#\ %s