re-structure neovim plugins

also delete unused ones

config/nvim/lua/aleidk/plugins-base/undo-tree.lua

@@ -0,0 +1,13 @@
+return {
+	{
+		"mbbill/undotree",
+		config = function()
+			vim.g.undotree_WindowLayout = 2
+			vim.g.undotree_ShortIndicators = 1
+			vim.g.undotree_SetFocusWhenToggle = 1
+		end,
+		keys = {
+			{ "<leader>fu", vim.cmd.UndotreeToggle, desc = "Undo tree" },
+		},
+	},
+}