add step to commit paper pdf to repo

.github/workflows/draft-pdf.yml

@@ -25,4 +25,10 @@ jobs:
           # This is the output path where Pandoc will write the compiled
           # PDF. Note, this should be the same directory as the input
           # paper.md
-          path: paper/paper.pdf
+          path: paper/paper.pdf
+      - name: Commit PDF to repository
+        uses: EndBug/add-and-commit@v9
+        with:
+          message: '(auto) Paper PDF Draft'
+          # This should be the path to the paper within your repo.
+          add: 'paper/paper.pdf' # 'paper/*.pdf' to commit all PDFs in the paper directory