Update toc.yml (SharePoint#9053)

Adding TOC entry for new topic How to export video transcripts using the migration API.

Author: JoanneHendrickson

docs/toc.yml

@@ -2113,6 +2113,8 @@
       href: apis/onenote-migration-service.md
     - name: Sensitivity Labels and the SharePoint Migration API
       href: apis/sp-migration-api-and-sensitivity-labels.md
+    - name: How to export video transcripts using the SharePoint Migration API
+      href: apis/migration-api-video-transcripts.md
     - name: Migration API
       items:
       - name: Import Migration API