[NonGNU ELPA] Treeview version 1.2.0

[ELPA update]

Version 1.2.0 of package Treeview has just been released in NonGNU ELPA.
You can now find it in M-x list-packages RET.

Treeview describes itself as:

  =================================
  A generic tree navigation library
  =================================

More at https://elpa.nongnu.org/nongnu/treeview.html

## Summary:

  emacs-treeview
  ==============

  Abstract Emacs Lisp framework for tree navigation. Based on this framework, 
specific libraries for particular
  hierarchical data can be implemented, for example, file systems.

  This document describes v1.1.1 of emacs-treeview. Consider [this 
notes](#updating-from-v100) for upgrading from v1.0.0. 

  A typical tree could look like the following:

  <pre>
     [+] Node 1
     [-] Node 2
      |    [+] Node 21
      |    [+] Node 22
      |    [-] Node 23
      |     |    [+] Node 231
      |     |      Leaf 231
      |     |      Leaf 232
      |     |      Leaf 233
      |    [+] Node 24
     [+] Node 3
     [+] Node 4
  </pre>

## Recent NEWS:

[Not provided 🙁]