Add a README file for 7x.2.x branch

Hi ,

I reviewed this patch . This patch LGTM.

kunal@LAPTOP-G4FTKS5H MINGW64 /c/xampp/htdocs/contributions/web/modules/contrib/fences-2849005 (2849005-add-a-readme)
$ git apply -v fences-add-readme-2849005-2.patch
Checking patch README.txt...
Applied patch README.txt cleanly.

RTBC ++ for #2 ,based on the above comments as well .

Creating an MR for making it easy for the maintainer to merge.

Please review and merge this MR . Thanks

Automatically closed - issue fixed for 2 weeks with no activity.