libreofficekit: add overview of tiled editing to README
libreofficekit: add overview of tiled editing to README

Change-Id: Ie4e28f9315c9de2062d63c5eb5e9c7481c719cef

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core