Add sample branding options to local config template

dev-server/templates/client-config.js.mustache

@@ -5,6 +5,14 @@
       // showHighlights: 'always',
       // theme: 'clean',
 
+      // Example branding:
+      // branding: {
+      //  appBackgroundColor: 'white',
+      //  ctaBackgroundColor: 'rgba(3, 11, 16, 1)',
+      //  ctaTextColor: '#eee',
+      //  selectionFontFamily: 'helvetica, arial, sans serif'
+      //},
+
       // Example focused user mode
       // focus: {
       //   user: {
@@ -12,6 +20,7 @@
       //     displayName: 'Freddy Potato',
       //   }
       // },
+
       // Example services config
       // services: [{
       //   apiUrl: 'http://localhost:5000/api',