added support for elixir (#403)

init.lua

@@ -51,4 +51,5 @@ require('lsp.terraform-ls')
 require('lsp.vim-ls')
 require('lsp.vue-ls')
 require('lsp.yaml-ls')
+require('lsp.elixir-ls')
 

lua/lsp/elixir-ls.lua

@@ -0,0 +1,10 @@
+require'lspconfig'.elixirls.setup{
+    cmd = { DATA_PATH .. "/lspinstall/elixir/elixir-ls/language_server.sh"};
+}
+
+-- needed for the LSP to recognize elixir files (alternativly just use elixir-editors/vim-elixir)
+vim.cmd([[
+  au BufRead,BufNewFile *.ex,*.exs set filetype=elixir
+  au BufRead,BufNewFile *.eex,*.leex,*.sface set filetype=eelixir
+  au BufRead,BufNewFile mix.lock set filetype=elixir
+]])