🔨🤖 Route /projects/owid-grapher-py/ to its CF Pages project

Adds an entry to the SUBPROJECTS map so the umbrella custom domain
serves owid-grapher-py docs through its dedicated owid-grapher-py-docs
Pages project. Paired with owid/owid-grapher-py#26.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: lucasrodes

_worker.js

@@ -14,6 +14,7 @@
 
 const SUBPROJECTS = {
   "/projects/etl/": "https://owid-etl-docs.pages.dev",
+  "/projects/owid-grapher-py/": "https://owid-grapher-py-docs.pages.dev",
 };
 
 export default {