.pure-form-message/message-inline don't have any examples or docs

[tivac]

http://purecss.io/forms/ says nothing about .pure-form-message or .pure-form-message-inline added in #32. They're pretty useful, so having them on the docs page seems important. I only discovered them by chance while reading the code to debug an unrelated issue (my fault, not pure's).

[AurelioDeRosa]

I think this issue doesn't belong here but to the pure-website repository. Anyway, thanks for highlight this point @tivac.

[ericf]

Moved to: https://github.com/yui/pure-site/issues/172