Suggestion -- add a preview key

[ms-jpq]

Hi there,

I love your plugin, and I noticed that you don't have a key that opens files without leaving the tree's window.

It's a simple thing to add, and I have attached a snippet below of how I have it in my config.

I think this is a common enough usecase to include in the plugin though.

    lv.tree_preview = function ()
      local pos = api.nvim_win_get_cursor(0)
      local tree = require "tree"
      tree.on_keypress("edit")
      bindings.exec[[LuaTreeClose]]
      bindings.exec[[LuaTreeOpen]]
      api.nvim_win_set_cursor(0, pos)
    end

    bindings.map.normal("<Tab>", ":lua lv.tree_preview()<CR>")

*I wrote some config wrappers in my code, but you get the idea