Fix nginx docs validation pid path

docs/test_codeblocks_manifest.py

@@ -240,7 +240,11 @@ def validate_non_running(snippet: Snippet, disposition: str) -> None:
         assert nginx.is_file() and os.access(nginx, os.X_OK)
         with tempfile.TemporaryDirectory(prefix="archivebox-docs-nginx-") as temp:
             config = Path(temp) / "nginx.conf"
-            config.write_text(f"events {{}}\nhttp {{\nserver {{\nlisten 8080;\n{snippet.code}\n}}\n}}\n")
+            config.write_text(
+                f"pid {temp}/nginx.pid;\n"
+                f"events {{}}\n"
+                f"http {{\nserver {{\nlisten 8080;\n{snippet.code}\n}}\n}}\n",
+            )
             result = subprocess.run(
                 [nginx, "-t", "-c", config, "-p", temp],
                 text=True,