add docs and update readme

Author: Keegan Cordeiro

README.md

@@ -29,6 +29,8 @@ If you are migrating to version 3.0.0 or above from an earlier version, please c
 
 If you are migrating to version 4.0.0 or above from an earlier version, please check the [V4 breaking changes details](./docs/V4_Breaking_Changes.md).
 
+If you are migrating to version 5.0.0 or above from an earlier version, please check the [V5 breaking changes details](./docs/V5_Breaking_Changes.md).
+
 ## Usage
 
 We support all the endpoints available in our API.

docs/V5_Breaking_Changes.md

@@ -0,0 +1,10 @@
+# V5 breaking changes details
+
+V5 removes the following fields from the Beam correlation results response;
+* features
+* phq_impact_sum
+* phq_spend_sum
+* phq_attendance_sum
+* phq_rank_count
+
+It is recommended to query features directly from [Features API](https://docs.predicthq.com/api/features/get-features)