Using file-tree
Info:
It is self explanatory. It explains how to use the file tree.
How to open?
You can open the file tree with <leader>e
How to toggle on and off the file tree?
You can do it with Ctrl + n
How to navigate between the file-tree and the buffers?
You can use Ctrl+h,j,k,l keys to navigate between the buffer and the file-tree or inside the file tree.
Tip
Seems like Ctrl+n is enough to open, toggle on and off the file-tree.