Rename to plain 'regex-repo' and update documentation for release.

[zanerock]

Overview

Let's put the package in the root (removing the '@liquid-labs' org qualification from the package name).

Deliverables

• [x] rename the package
• [x] add 'css' and 'javascript' to the keywords

[zanerock]

Work for this issue will begin begin on branch work-liquid-labs/regex-repo/29.