Fixes #858 Docs issue on css guide
Merge branch 'master' of github.com:Semantic-Org/Semantic-UI
Fixes #813 issue in modal docs with maxLength
Fixes #827 issue with overview/definition mode leaving code examples visible
Fixes #810, modal missing html examples
Builds version 0.18.0 for release
Clarifying intended use of the secondary menu (fixes #875)
Update CDN info for JSFdelivr
Add CDN header
Merge pull request #881 from ewiner/master

Clarifying intended use of the secondary menu (fixes #875)
Update README.md
Update RELEASE NOTES.md
Update RELEASE NOTES.md