Update TOC.yml

Author: mduelae

powerapps-docs/maker/TOC.yml

@@ -1162,7 +1162,7 @@
       href: ./canvas-apps/how-to/deep-linking.md
     - name: Work with the PDF function (experimental)
       href: ./canvas-apps/how-to/pdf-function.md
-  - name: Preview and app
+  - name: Preview an app
     href: ./canvas-apps/preview-app.md
   - name: Save and publish an app
     href: ./canvas-apps/save-publish-app.md