Revert "refactor(nvim): remove headlines.nvim"

This reverts commit 4387a2b362.

dots/.nvim-environments/primary/config/lua/plugins/plugins.lua

@@ -843,6 +843,16 @@ lazy.setup({
         "famiu/bufdelete.nvim",
         event = "VeryLazy",
     },
+
+    -- Improved Visuals for Documentation
+    {
+        "lukas-reineke/headlines.nvim",
+        after = { "nvim-treesitter" },
+        event = "VeryLazy",
+        config = function()
+            require("headlines").setup()
+        end,
+    },
 }, {
     checker = {
         enabled = true,