Update advanced.md

Changed file name in text from '_config.html' to '_config.js' and how that row actually looks like today (`debug: true,`).
Merge pull request #4 from stefantagt/patch-1

Update advanced.md
Update buildingApps.md

Added { in div to insert app in html.
Did som spelling corrections
Changed some icon tags that was incorect
Create README.md
Update
Merge branch 'master' into mhe