Document autopush Pings

[data-sync-user]

autoconnect deals with 2 different ping types. Let’s add a quick document explaining their usage because they’re obscure and easily confused between each other.

Assigning to me because I already have a short draft of this.

┆Issue is synchronized with this Jira Task

[data-sync-user]

➤ Philip Jenvey commented:

This comment’s related: https://mozilla-hub.atlassian.net/browse/SYNC-3846?focusedCommentId=718382 ( https://mozilla-hub.atlassian.net/browse/SYNC-3846?focusedCommentId=718382|smart-link )