adding docs on how to add multiple middleware at once. #157

showing just call and moving to declarations

single example and triple example for app.use

usage example seems to large for the api/index file, moving it to guide with better example

fixing md style and moving pi to math.pi

code consistancy

adding spaces
Merge branch 'docs/app-use-multi' of github.com:mcwhittemore/koa into docs/app-use-multi

Conflicts:
	docs/guide.md