Flesh out README.md and clarify RE names

[zanerock]

Overview

We need to get the README.md in shape.

Deliverables

• update 'catalyst-resource-jest' and update coverage with improved counting
• add 'Install' section
• add 'Usage' section
• add 'Regex reference' section (built from regexes)
• update RE names for clarity

[zanerock]

Work for this issue will begin begin on branch work-liquid-labs/regex-repo/17.