Documentation: Clean up README-specific docs

[ablwr]

See context in #250 and shared document there.

[lbjohnson01]

Hi, it's basically ready, although we should settle a spelling issue.

SignalServer
signalserver
Signalserver

The first one is my personal preference. Thoughts?

[lbjohnson01]

Also, please find a separate working document for the README here: https://docs.google.com/document/d/1xN2zw9HNLl2pxzlbst_2bjR_JV5OMgJ2WcjzaSIU6RY/edit

[ablwr]

This has come up before... I believe SignalServer was the consensus. (No space between).