readme terminolgy: feed vs core

[DougAnderson444]

Hey guys, was just reading through the readme and noticed both the terms feed and core, it got a bit confusing to know whether core was referring to a hypercore or a corestore, so I propose consistently calling hypercores feed and calling corestores stores? Unless of courses feeds are now called cores?

Anyway, for your consideration, made the tweaks that might help clarify? Thanks for this work, I'm a big fan.