fix YamlMime header

jdanyow · web-flow · commit 60b8160b323e · 2019-12-19T17:18:21.000-08:00
```diff - # YamlMime:ZonePivotGroups + ### YamlMime:ZonePivotGroups ``` https://ceapex.visualstudio.com/Engineering/_workitems/edit/155512
diff --git a/articles/zone-pivot-groups.yml b/articles/zone-pivot-groups.yml
@@ -1,4 +1,4 @@
-# YamlMime:ZonePivotGroups
+### YamlMime:ZonePivotGroups
 groups:
 - id: programming-languages-set-one
   title: Programming languages

Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-# YamlMime:ZonePivotGroups`
	`1`	`+### YamlMime:ZonePivotGroups`
`2`	`2`	`groups:`
`3`	`3`	`- id: programming-languages-set-one`
`4`	`4`	`title: Programming languages`