docs(router): copyedits and moved code excerpt earlier (#3133)
docs(router): copyedits and moved code excerpt earlier (#3133)

- Copyedits
- Link directly to APP_BASE_HREF API entry, no need for a callout.
- Put dragon-anchor routerLink example *before* the detailed bulleted
list that analyzes it.
realappie/angular.io,realappie/angular.io,realappie/angular.io,realappie/angular.io,realappie/angular.io