add elixir nvim plugin

dot_config/nvim/lua/plugins/elixir.lua

@@ -0,0 +1,17 @@
+-- Set up elixir-tools.nvim for better Elixir support
+
+return {
+  {
+    "elixir-tools/elixir-tools.nvim",
+    event = { "BufReadPre", "BufNewFile" },
+    config = function()
+      local elixir = require("elixir")
+
+      elixir.setup({
+        nextls = { enable = true },
+        credo = {},
+        elixirls = { enable = false },
+      })
+    end,
+  },
+}