Restructure Darwin configuration

So far, this is just based on mightymac. The other devices will be
updated soon.

modules/hosts/common/files/nvim/lua/plugins/lualine.lua

@@ -0,0 +1,19 @@
+return {
+  "nvim-lualine/lualine.nvim",
+  config = function()
+    require("lualine").setup({
+      options = {
+        icons_enabled = true,
+        -- theme = "dracula-nvim",
+      },
+      sections = {
+        lualine_a = {
+          {
+            "filename",
+            path = 1,
+          },
+        },
+      },
+    })
+  end,
+}