fix:usr: github reference card url has changed, so we updated it
new:usr: add videos to the github lesson
chg: dev: Update changelog
new:usr: added a 2 part video about the Web page structure
new:usr: added the first three videos to introduce the class content
new:dev: add contributors
new:dev: layout with localtoc and version
3.0
Merge branch 'master' of https://github.com/cloudmesh/classes