added default colormode and example navbar

docusaurus.config.js

@@ -45,6 +45,16 @@ const config = {
           autoCollapseCategories: false,
         },
       },
+      colorMode: {
+        defaultMode: "light",
+        respectPrefersColorScheme: true
+      },
+      announcementBar: {
+        id: "announcement-bar",
+        content: '⭐️ Like the new developer community design? Want to tell us what you think? Let us know in the  <a target="_blank" rel="noopener noreferrer" href="https://developer.sailpoint.com/discuss/c/feedback/2">Developer Community Forum</a>.',
+        backgroundColor: "#0388fc",
+        isCloseable: true
+      },
       navbar: {
         title: '',
         logo: {