[SYNPY-1637] Add 'Contact Us' section with support link in navigation (#1230)

Author: BryanFauble

mkdocs.yml

@@ -128,6 +128,7 @@ nav:
       - Structuring Your Project: explanations/structuring_your_project.md
   - News:
       - news.md
+  - Contact Us: https://sagebionetworks.jira.com/servicedesk/customer/portal/9/group/16/create/206
 
 # Theme configuration
 theme: