tweak readme to better convey that startErgScan is a stream of single instances

Author: MoralCode

README.md

@@ -47,7 +47,7 @@ ErgBleManager bleManager = ErgBleManager();
 bleManager.init(); //ready to go!
 ```
 ### Scanning for devices
-Next, you need to start scanning for available devices. This uses a Stream that returns instances of the `Ergometer` class. Each of these instances represents an erg and can be saved for later reuse.
+Next, you need to start scanning for available devices. This uses a Stream to return an instance of the `Ergometer` class for each erg found. Each of these instances represents an erg and can be saved for later reuse.
 
 **Important:** This library leaves things like permissions up to the application using the library. Many of these setup steps will fail if bluetooth is off or if permissions are not correct. It is the responsibility of users of this API to ensure permissions are correct before beginning a bluetooth scan.