feat: perform undo and redo with `strg+z` in visual mode

lua/config/keys.lua

@@ -20,13 +20,13 @@ local keymaps = {
         desc = "Write buffer to disk"
     },
     {
-        mode = { 'n', 'i' },
+        mode = { 'n', 'v', 'i' },
         keys = '<C-z>',
         cmd  = vim.cmd.undo,
         desc = "Undo last edit"
     },
     {
-        mode = { 'n', 'i' },
+        mode = { 'n', 'v', 'i' },
         keys = '<C-y>',
         cmd  = vim.cmd.redo,
         desc = "Redo last edit that was undone"