Merge branch 'docs/edit-event-tracking' into 'master'

Edits to event tracking topic

Closes #65431

See merge request gitlab-org/gitlab-ce!31457

doc/development/fe_guide/event_tracking.md

-# Event Tracking
+# Event tracking
 
-We use a tracking interface that wraps up [Snowplow](https://github.com/snowplow/snowplow) for tracking custom events. Snowplow implements page tracking, but also exposes custom event tracking.
+GitLab provides `Tracking`, an interface that wraps
+[Snowplow](https://github.com/snowplow/snowplow) for tracking custom events.
+It uses Snowplow's custom event tracking functions.
 
 The tracking interface can be imported in JS files as follows: