Sky Uk Css Versions Save

• Update Stylelint dependencies
• Change deprecated selector-no-id to selector-max-id

• Update Stylelint to 7.9.0 and deprecate any rules to be removed in 8.0.0
• Update BEM examples in README.md

• Rebrand package name to sky-css-lint to stylelint-config-sky-uk
• Remove default .stylelintrc for symlinking.
• Use index.js to extend rules.

First draft of .stylelintrc configuration and general guidelines.

Initial .stylelintrc configuration and WIP documentation