Update dependabot.yml

Author: binon

.github/dependabot.yml

@@ -5,11 +5,14 @@
 
 version: 2
 registries:
-  - private-nuget:
-      type: nuget-feed
-      url: "https://pkgs.dev.azure.com/e-LfH/_packaging/LearningHubFeed/nuget/v3/index.json"
-      username: "kevin.whittaker" 
-      password: ${{ secrets.AZURE_DEVOPS_PAT }}   
+  private-nuget:
+    type: nuget-feed
+    url: "https://pkgs.dev.azure.com/e-LfH/_packaging/LearningHubFeed/nuget/v3/index.json"
+    username: "kevin.whittaker" 
+    password: ${{ secrets.AZURE_DEVOPS_PAT }}   
+  public-nuget:
+    type: nuget-feed
+    url: "https://api.nuget.org/v3/index.json"  
 updates:
   - package-ecosystem: "nuget" 
     directory: "/" # Location of package manifests