Review UI text in custom notification settings

Problem to solve

Options in custom notification settings need a TW review for wording and sorting:

Related doc: https://docs.gitlab.com/ee/user/profile/notifications.html#notification-events-on-issues-merge-requests-and-epics

Screenshot

Current text	Proposed
Custom notification events
Notification events
Custom notification levels are the same as participating levels. With custom notification levels you will also receive notifications for select events. To find out more, check out notification emails.	With custom notification level you receive notifications for the same events as in the Participate level, with additional selected events. For more information, see notification emails.
New release	Release is created
New note	Comment is added
New issue	Issue is created
Reopen issue	Issue is reopened
Close issue	Issue is closed
Reassign issue	Issue is reassigned
Issue due	Issue is due soon
New merge request	Merge request is created
Push to merge request	Merge request receives a push
Reopen merge request	Merge request is reopened
Close merge request	Merge request is closed
Reassign merge request	Merge request is reassigned
Change reviewer merge request	Merge request reviewers are changed
Merge merge request	Merge request is merged
Failed pipeline	Pipeline fails
Fixed pipeline	Pipeline is fixed
Successful pipeline	Pipeline is successful
Moved project	Project is moved
Merge when pipeline succeeds	Merge request is set to auto-merge
New epic	Epic is created
Added as approver	You are added as an approver on a merge request

Proposal

Who can address the issue

@msedlakjakubowski, TW for groupproject management + @nickleonard to review

Other links/references