Fixed deploy script (#28)

Author: scudette

.github/workflows/gh-pages.yml

@@ -37,7 +37,7 @@ jobs:
 
       - name: Deploy
         uses: peaceiris/actions-gh-pages@v3
-        if: github.ref == 'refs/heads/master'
+        if: github.ref == 'refs/heads/main'
         with:
           github_token: ${{ secrets.GITHUB_TOKEN }}
           publish_dir: ./docs/public