Silent payments in the Guide

[yashrajd]

This is a draft pull request for silent payments content in the guide. It is ready for review but not ready to merge just yet even if feedback is fine. I was able to able to create server and preview all of the content on local.

Preview the silent payments page

Listing a few minor of to-do's below, apart from the any changes necessitated by feedback:

• [x] add mobile images for most screens
• [x] add alt-text, captions to some screens
• [x] [optional] improve header image
• [x] refine copy

Look forward to review and feedback by way of suggestions, corrections for screens and content keeping in mind the above to-dos, which I will complete in a few days. I would discourage inputs on approach unless they were really necessary. I wanted to put this out there so the wider community in general could preview & review it.