docs: transfer state

docs/scully-lib-core.md

@@ -97,6 +97,22 @@ getState<T>(name: string): Observable<T>
 setState<T>(name: string, val: T): void;
 ```
 
+#### useScullyTransferState
+
+`useScullyTransferState` - Wraps an observable into scully's transfer state.
+
+If data for the provided `name` is available in the state, it gets returned. Otherwise,
+the `originalState` observable will be returned.
+
+On subsequent calls, the data in the state will always be returned. The `originalState` will
+be returned only once.
+
+This is a convenience method which does not require you to use `getState`/`setState` manually.
+
+```typescript
+useScullyTransferState<T>(name: string, originalState: Observable<T>): Observable<T>;
+```
+
 ## utility-methods
 
 These methods provide useful information about Scully processes.

libs/ng-lib/src/lib/transfer-state/transfer-state.service.ts

@@ -188,6 +188,19 @@ export class TransferStateService {
     this.nextUrl.subscribe();
   }
 
+  /**
+   * Wraps an observable into scully's transfer state. If data for the provided `name` is
+   * available in the state, it gets returned. Otherwise, the `originalState` observable will
+   * be returned.
+   * 
+   * On subsequent calls, the data in the state will always be returned. The `originalState` will
+   * be returned only once.
+   * 
+   * This is a convenience method which does not require you to use `getState`/`setState` manually.
+   *
+   * @param name state key
+   * @param originalState an observable which yields the desired data
+   */
   useScullyTransferState<T>(
     name: string,
     originalState: Observable<T>