Move md-to-pdf to system

.drone.yml

@@ -1,11 +1,15 @@
 kind: pipeline
+type: exec
 name: create_pdf_release
 
 steps:
+  - name: install_mdpdf
+    commands:
+      - npm i md-to-pdf
+
   - name: render_md
     image: node
     commands:
-      - npm install
       - npm run build
   
   - name: gitea_release