Fix typo in README

Change an underscore to a hyphen.

Change-Id: Ifb37786dea7f17c2f547b9104caa7a62cf2e041f
Reviewed-on: https://gerrit.causes.com/32590
Reviewed-by: Shane da Silva <shane@causes.com>
Tested-by: jenkins <jenkins@causes.com>
Unify code block style in README

Consistently use triple backtick syntax for code blocks.

Change-Id: I924fbc24c21671fc2ae8affb2aade1245f35e34e
Reviewed-on: https://gerrit.causes.com/32591
Tested-by: jenkins <jenkins@causes.com>
Reviewed-by: Shane da Silva <shane@causes.com>
add case for selector with function call

the SingleLinePerSelector linter should not report a lint if the
interpolated selectors contains a comma inside a function (e.g. nth)