Update "status changes" to "events" in provider

I noticed a few places in the provider README where it
was still referring to "status changes" instead of the new
term "events". There was also an inconsistency in the depiction
of the response format.

Author: jiffyclub

provider/README.md

@@ -395,7 +395,7 @@ The `/events/historical` API uses the following query parameter:
 
 | Query Parameter    | Format | Expected Output |
 | ---------    | ------ | --------------- |
-| `event_time` | `YYYY-MM-DDTHH`, an [ISO 8601](https://en.wikipedia.org/wiki/ISO_8601) extended datetime representing an UTC hour between 00 and 23. | All status changes with an event time occurring within the hour. For example, requesting `event_time=2019-10-01T07` returns all status changes where `2019-10-01T07:00:00 <= status_change.event_time < 2019-10-01T08:00:00` UTC. |
+| `event_time` | `YYYY-MM-DDTHH`, an [ISO 8601](https://en.wikipedia.org/wiki/ISO_8601) extended datetime representing an UTC hour between 00 and 23. | All events with an event time occurring within the hour. For example, requesting `event_time=2019-10-01T07` returns all events where `2019-10-01T07:00:00 <= event.timestamp < 2019-10-01T08:00:00` UTC. |
 
 Without an `event_time` query parameter, `/events` shall return a `400 Bad Request` error.
 
@@ -411,14 +411,14 @@ processing for that hour:
 * For hours that are in the past but for which data is not yet available
   the API shall return a `202 Accepted` response.
 * For all other hours the API shall return a `200 OK` response with a fully
-  populated body, even for hours that contain no status changes to report.
-  If the hour has no status changes to report the response shall contain an
-  empty array of status changes:
+  populated body, even for hours that contain no events to report.
+  If the hour has no events to report the response shall contain an
+  empty array of events:
 
     ```json
     {
         "version": "x.y.z",
-        "status_changes": []
+        "events": []
     }
     ```