Improve instructions for use

Some who come across the plugin who are relatively IndieWeb-aware don’t know how to use the plugin:
eg: https://islandinthenet.com/saturday-16-february-2019-1017am/ which has resulted in some unintended spam in the IndieNews feed.

What exactly are the triggers for syndicating to IndieWeb News and Indieweb.xyz? Is it just having a tag indienews, indieweb, or even indie* where * is a wildcard? Are there others I may be missing?

Can one target other subs within indieweb.xyz (examples: /en/longreads or /en/games/) or just the /language/indieweb/ sub with the plugin? How is differentiating them done from the user’s perspective? I do see a reference to the /hottubs/ sub in the code, but I’m not following all the logic there.

I suspect it would also be nice to have some details about the dashboard widget and news feeds as well as listing a requirement for the Webmention plugin which some might not know about.

I’m happy to modify the readme’s with better instructions if I can be a bit more clear on some of what the code is doing with regard to the above.