Make TagBot able to deploy docs

Author: andreasnoack

.github/workflows/CompatHelper.yml

@@ -12,5 +12,5 @@ jobs:
       - name: CompatHelper.main()
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-          COMPATHELPER_PRIV: ${{ secrets.COMPATHELPER_PRIV }}  # optional
+          COMPATHELPER_PRIV: ${{ secrets.DOCUMENTER_KEY }}  # optional
         run: julia -e 'using CompatHelper; CompatHelper.main()'