Tree.nvim lua config user interface

[zgpio]

-- keymap(keys, action1, action2, ...)  action can be `vim action` or `tree action`
tree.keymap('cp', 'copy')
tree.keymap('s', {'drop', 'split'})
tree.keymap('s', {'multi', {{'drop', 'split'}, 'quit'}})
tree.keymap('s', {'drop', 'split'}, 'quit')
tree.keymap('cd', {'cd', {'.'}})
-- tree action and vim action
tree.keymap('<Tab>', 'toggle_select', 'j')
-- callable need eval every time
tree.keymap([[\]], {'cd', vim.fn.getcwd})

[zgpio]

Partially completed, waiting for neovim autocmd lua api and lua callback. Ref to neovim/neovim#12378

[zgpio]

Completed.