Bug 1402026: Correct formatting for AS telemetry bulleted lists. r=liuche

Apparently, if you don't have whitespace above the bulleted list, it won't
format as a list.

MozReview-Commit-ID: LiLpSNScBxR

--HG--
extra : rebase_source : b3ec064a98a531aab5f38d7f4b3f338499010e97

mobile/android/docs/activitystreamtelemetry.rst

@@ -142,6 +142,7 @@ For both event types, in addition to global extras, the following information is
     }
 
 Subtype indicates reason an item being which is being interacted with appeared in the Highlights:
+
 - "visited": a website has been visited recently
 - "bookmarked": a website has been bookmarked recently