Update sidenav.yml

Author: michelle-luna

jekyll/_data/sidenav.yml

@@ -181,7 +181,7 @@
         - name: Configuration Reference
           link: 2.0/configuration-reference
         - name: API Reference
-          link: api/
+          link: api/v1-reference/
         - name: Prebuilt Images
           link: 2.0/circleci-images/
         - name: Glossary