Expose RouterJS' TypeScript types publicly

[theseyi]

The types for public interfaces should be exposed publicly to users who want to consume the types in their application, e.g. EmberJS users.

For example, the Ember Router class method didTransition has parameters that are passed in on invocation

router.js/lib/router/handler-info.ts

Line 324 in 73d6a7f

export class ResolvedHandlerInfo extends HandlerInfo {

These types are not defined in the Ember JS typings and it's currently not easy to just install and import the router_js types
EDIT: #238 seems like it be related to the issues encountered with importing

[theseyi]

Any interest in resolving this issue?

[Bnaya]

yes! :)