[added] Router.makeHref

promoting this to public API so others can use it
to build components like `<Link/>`

closes remix-run#168

docs/api/Router.md

@@ -51,3 +51,16 @@ entry from the browser history.
 Router.goBack();
 ```
 
+### `makeHref(routeName, params, query)`
+
+Creates an `href` to a route. Use this along with `ActiveState` when you
+need to build components similar to `Link`.
+
+#### Example
+
+```js
+// given a route like this:
+<Route name="user" path="users/:userId"/>
+Router.makeHref('user', {userId: 123}); // "users/123"
+```
+

index.js

@@ -6,3 +6,4 @@ exports.Routes = require('./Routes');
 exports.goBack = require('./goBack');
 exports.replaceWith = require('./replaceWith');
 exports.transitionTo = require('./transitionTo');
+exports.makeHref = require('./makeHref');

makeHref.js

@@ -0,0 +1 @@
+module.exports = require('./modules/helpers/makeHref');