create .nojekyll file in OUT_DIR (#84)

This tells GitHub this is not a Jekyll site. This way GitHub does not attempt to build it with Jekyll resulting in faster deployments.

entrypoint.sh

@@ -90,6 +90,9 @@ main() {
         echo "Pushing artifacts to ${TARGET_REPOSITORY}:$remote_branch"
 
         cd "${OUT_DIR}"
+
+        touch .nojekyll
+
         git init
         git config user.name "GitHub Actions"
         git config user.email "github-actions-bot@users.noreply.${GITHUB_HOSTNAME}"