vendor-prefix-align: `khtml` prefix added

`-khtml` is really needed on special project for old browsers (Yandex lite version).
Consistently use double quotes in JSON examples.
Fix acceptable values showing as code.
Docs: Update options order
v3.0.1
Fixed the link to the CSScomb Core
Fixed the markup for code inside list items
Merge pull request #292 from kizu/patch-3

Fixed the link to the CSScomb Core in changelog
Added TOC and added link to docs folder
Renamed to contributing to enable github features
Merge pull request #293 from kizu/patch-4

A bit of love for contribution guidelines
New option: space-between-rulesets
implementing rule-delimeter option with a couple of tests
implementing rule-delimeter option with a couple of tests
implementing more tests, added preceeding search
remove copypaste
added loop support
Добавил папку rule-delimiter-less с правилами
adding less rules
new tests