Add JS API doc to sidebar nav

Author: crandmck

docs/js-sdk/sidebars.js

@@ -12,6 +12,11 @@ const sidebars = {
           label: 'C2PA web library',
           id: 'c2pa-js/readme',
         },
+        {
+          type: 'link',
+          label: 'API documentation',
+          href: 'https://contentauth.github.io/c2pa-js/',
+        },
         {
           type: 'link',
           label: 'GitHub',