Readme notes

Problem/Motivation

First contact with danse and push_notifications fw, And while I am trying to understand and install in a test site, I could get some features working with pf_notifications (but with issues), so I started from scratch again this time using onesignal but I cannot get it working, while I have everything set (as I suppose it needs to be), I cannot even get the notice from the browser about allowing notifications...
Please, could you elaborate at least a raw readme.md to achieve the minimal configuration to make it work? Thanks in advance