[BEE-62243] Update help

Author: jeromepochat

src/main/resources/org/jenkinsci/plugins/github_branch_source/app_credentials/AccessSpecifiedRepositories/help-owner.html

@@ -1,5 +1,8 @@
 <p>
     The organization or user that this credential is to be used for.
-    If left blank, and the GitHub App is only installed in a single organization, then these
-    credentials will be able to access that organization in any context in Jenkins.
+    If left blank:
+    <ul>
+      <li>If the GitHub App is installed in a single organization, then these credentials will be able to access that organization in any context in Jenkins.</li>
+      <li>If the GitHub App is installed in multiple organizations, then the owner will be inferred from the context where inference is supported.</li>
+    </ul>
 </p>