Create Core.CDNManager.yml

Added YAML file so that this tool can be pulled into the Office and M365 resource galleries automatically (https://developer.microsoft.com/en-us/office/gallery)

Author: nokafor

Solutions/Core.CDNManager/Core.CDNManager.yml

@@ -0,0 +1,14 @@
+page_type: sample
+products:
+  - office-sp
+languages:
+  - csharp
+extensions:
+  contentType: tools
+  technologies:
+    - Add-ins
+  createdDate: '1/1/2016 12:00:00 AM'
+  scenarios:
+    - Embed
+title: Manage CDN references for JavaScript libraries (Core.CDNManager)
+description: The CDN Manager is used to manage Content Delivery Network (CDN) references for JavaScript Libraries and Cascading Style Sheets (CSS) in SharePoint 2013 sites.