Almost 50% or more of whatsapp content is either takenup from websites or made by customizing content from web.
Idea 1 - Share via WhatsApp social icon
So, why not ease the lives by a "share via whatsapp" social icon, in each website page, when clicked will popup a box asking for the phone number of the friend / friends or group name and then send the link (or the page content) to the group?
Idea 2 - WhatsApp editor extension
Why not build a browser extension, which shall popup a window - allowing to copy/paste content or edit content and send it to a selected friend / friends or group?