update PR template

Author: sdwheeler

.github/PULL_REQUEST_TEMPLATE.md

@@ -10,13 +10,22 @@ have version folders.
 
 Version(s) of documents impacted
 
+**Cmdlet reference & about_ topics**
 - [ ] Impacts 7 document
 - [ ] Impacts 6 document
 - [ ] Impacts 5.1 document
 - [ ] Impacts 5.0 document
 - [ ] Impacts 4.0 document
 - [ ] Impacts 3.0 document
 
+**Conceptual articles**
+- [ ] PowerShell articles
+- [ ] DSC articles
+- [ ] Gallery articles
+- [ ] JEA articles
+- [ ] WMF articles
+- [ ] SDK articles
+
 ## PR Checklist
 
 - [ ] I have read the [contributors guide](https://github.com/MicrosoftDocs/PowerShell-Docs/blob/staging/CONTRIBUTING.md) and followed the style and process guidelines