Update docs for alerts and event review

docs/docs/configuration/events.md

@@ -0,0 +1,24 @@
+---
+id: events
+title: Events
+---
+
+Events are saved as periods of time where active objects are detected. After watching the preview of an event it is marked as reviewed.
+
+## Restricting alerts to specific object types
+
+By default an event will only be marked as an alert if a person or car is detected. This can be configured using the following config:
+
+```yaml
+# can be overridden at camera level
+objects:
+  alert:
+    - car
+    - cat
+    - dog
+    - person
+```
+
+## Restricting alerts to specific zones
+
+By default an event will be marked as an alert if any `objects -> alert` is detected anywhere in the camera frame. You will likely want to configure events to only be marked as an alert when the object enters an area of interest, [see the zone docs for more information](./zones.mdzones#restricting-alerts-to-specific-zones)

docs/docs/configuration/zones.md

@@ -14,9 +14,9 @@ During testing, enable the Zones option for the debug feed so you can adjust as
 
 To create a zone, follow [the steps for a "Motion mask"](masks.md), but use the section of the web UI for creating a zone instead.
 
-### Restricting events to specific zones
+### Restricting alerts to specific zones
 
-Often you will only want events to be created when an object enters areas of interest. This is done using zones along with setting required_zones. Let's say you only want to be notified when an object enters your entire_yard zone, the config would be:
+Often you will only want alerts to be created when an object enters areas of interest. This is done using zones along with setting required_zones. Let's say you only want to have an alert created when an object enters your entire_yard zone, the config would be:
 
 ```yaml
 cameras: