add WAI-CooP Symposium

Author: shawna-slh

navigation.yml

@@ -491,6 +491,9 @@
     pages:
     - name: WAI-CooP
       url: "/about/projects/wai-coop/"
+      pages:
+      - name: Online Research Symposium
+        url: "/about/projects/wai-coop/symposium1/"	  
     - name: WAI-Guide
       url: "/about/projects/wai-guide/"
     - name: WAI-Tools