Merge pull request #119 from evs-chris/updates

Updates for un(der)documented and new features
Ractive now uses native promises
Create Using Ractive with Yeoman.md.hbs
Update Tips.md.hbs
add unless special section and note how else works within the each section
add a short section on updating partials after initial render
document ractive array methods pop, push, shift, splice, and unshift