Fix GPE version

Use `~3.0.0-0` instead of `~3.0.0` to be able to use GPE 3.0.0-10 and
greater.
v3.0.2
Fixed the link to the CSScomb Core
Fixed the markup for code inside list items
Added TOC and added link to docs folder
Renamed to contributing to enable github features
npmignore non-essential files
Fix #317: sort-order should not remove empty lines
v3.0.3