update ajs2 upgrade docs[netlify-build]

Author: markzegarelli

src/connections/sources/catalog/libraries/website/javascript/upgrade-to-ajs2.md

@@ -39,7 +39,14 @@ In some cases, upgrading to Analytics.js 2.0 requires manual effort beyond enabl
 
 ### When using in-domain instrumentation CDN aliasing
 
-If the source you intend to upgrade uses the in-domain instrumentation as well as a custom "Alias for analytics.js", then you should update the AJS snippet to the latest version (4.13.2 or higher) before you toggle on Analytics.js 2.0. 
+If the source you intend to upgrade uses the in-domain instrumentation as well as a custom "Alias for analytics.js", then you should update the AJS snippet to the latest version (4.13.2 or higher) before you toggle on Analytics.js 2.0.
+
+To ensure that AJS is loaded from your indomain CDN, add the following to your javascript snippet, directly after `analytics._writeKey="<WRITE_KEY>";`:
+
+- `analytics._cdn="<YOUR_CDN_URL>"`
+
+The updated snippet should read `...analytics._writeKey="<WRITE_KEY>";analytics._cdn="<YOUR_CDN_URL>"`.
+
 
 ### When relying on Analytics.js Classic's `ajs_anonymous_id` cookie format