Update indoor's readme "How it works" with IndoorPositioningDefinition step

Author: shubham7109

samples/show-device-location-using-indoor-positioning/README.md

@@ -17,7 +17,7 @@ When there is no IPS beacons nearby, or other errors occur while initializing th
 ## How it works
 
 1. Load an IPS-enabled map. This can be a web map hosted as a portal item in ArcGIS Online, an Enterprise Portal, or a mobile map package (.mmpk) created with ArcGIS Pro.
-2. Create an `IndoorsLocationDataSource` with the positioning feature table (stored with the map) and the pathways feature table after both tables are loaded.
+2. Create and load an `IndoorPositioningDefinition` (stored with IPS-aware maps), then create an `IndoorsLocationDataSource` from it. 
 3. Handle location change events to respond to floor changes or read other metadata for locations.
 4. Assign the `IndoorsLocationDataSource` to the map view's location display.
 5. Enable and disable the map view's location display using `LocationDisplay.dataSource.start()` and `LocationDisplay.dataSource.stop()`. Device location will appear on the display as a blue dot and update as the user moves throughout the space.