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
Fix typo
update CONTRIBUTING.md

Tripped across this; not sure if other pages need to be changed.
+ http://csscomb.com/config tip
Merge pull request #324 from tomByrer/patch-1

update CONTRIBUTING.md
Merge pull request #325 from tomByrer/patch-2

+ http://csscomb.com/config tip
Merge pull request #318 from gonzalocasas/patch-1

Fix typo
Fix Gonzales version: 3.0.0-10
v3.0.4