Change TagBot to use existing changelog

Signed-off-by: Thomas A. Christensen II <25492070+MillironX@users.noreply.github.com>

.github/workflows/TagBot.yml

@@ -9,7 +9,11 @@ jobs:
     if: github.event_name == 'workflow_dispatch' || github.actor == 'JuliaTagBot'
     runs-on: ubuntu-latest
     steps:
+      - uses: actions/checkout@v2
+      - uses: ffurrer2/extract-release-notes@v1
+        id: extract-release-notes
       - uses: JuliaRegistries/TagBot@v1
         with:
           token: ${{ secrets.GITHUB_TOKEN }}
           ssh: ${{ secrets.DOCUMENTER_KEY }}
+          changelog: ${{ steps.extract-release-notes.outputs.release_notes }}