feat: add tmux navigator, undotree

kickstart/lua/custom/plugins/tmux_navigator.lua

@@ -0,0 +1,17 @@
+return {
+  'christoomey/vim-tmux-navigator',
+  cmd = {
+    'TmuxNavigateLeft',
+    'TmuxNavigateDown',
+    'TmuxNavigateUp',
+    'TmuxNavigateRight',
+    'TmuxNavigatePrevious',
+  },
+  keys = {
+    { '<c-h>', '<cmd><C-U>TmuxNavigateLeft<cr>' },
+    { '<c-j>', '<cmd><C-U>TmuxNavigateDown<cr>' },
+    { '<c-k>', '<cmd><C-U>TmuxNavigateUp<cr>' },
+    { '<c-l>', '<cmd><C-U>TmuxNavigateRight<cr>' },
+    { '<c-\\>', '<cmd><C-U>TmuxNavigatePrevious<cr>' },
+  },
+}

kickstart/lua/custom/plugins/undotree.lua

@@ -0,0 +1,6 @@
+return {
+  'mbbill/undotree',
+  keys = {
+    { '<leader>u', '<cmd> UndotreeToggle <CR>', desc = 'Toggle [U]ndotree', mode = { 'n' } },
+  },
+}