Update main.yml

Author: shenhuan2021

.github/workflows/main.yml

@@ -25,7 +25,7 @@ jobs:
       
       - name: Convert Markdown to PDF
         run: |
-          md-to-pdf README.md > README.pdf
+            find doc -name "README.md" -exec sh -c 'md-to-pdf "$1" > "${1%}.pdf"' _ {} \;
       
       - name: Upload PDF
         uses: actions/upload-artifact@v4