Extend HMI:JsonTable, create Edit CSV POU, create example, add some doc (#41)

* Extend Jsontable widget, create Edit CSV POU, create example for both

* Add doc for HMI:Image and HMI:JsonTable

* Expand example to include HMI:Image

SVGHMI
======

Contents:

.. toctree::
   :maxdepth: 2

   intro
   syntax
   pages
   clones
   groups
   variables
   configuration
   i18n
   fonts
   hacking
   widgets
   library