migrate nvim config to 0.12.0: vim.pack, ui2, snacks -> mini, just general spring cleaning

nvim/plugin/visual-whitespace.lua

@@ -0,0 +1,8 @@
+vim.api.nvim_create_autocmd("ModeChanged", {
+    pattern = "*:[vV\22]",
+    once = true,
+    callback = function()
+        vim.pack.add({ "https://github.com/mcauley-penney/visual-whitespace.nvim" })
+        require("visual-whitespace").setup({})
+    end,
+})