cugraph: explicitly mention libraries by name on API docs page

[jameslamb]

Follow-up to #669 (comment)

@bdice's comment there highlights that the API docs for cuGraph and its ecosystem of related libraries can be a bit hard to find right now. At https://docs.rapids.ai/api/, you see individual entries for cudf, dask-cudf, Java + cudf, and libcudf, but only a single cuGraph entry.

I believe this is intentional (@acostadon please correct me), and it's related to the fact that cugraph-related libraries have all their docs built and combined together in a dedicated repo: https://github.com/rapidsai/cugraph-docs

When you click the Stable (25.08) link on that API docs page, you're directed to https://docs.rapids.ai/api/cugraph/stable/, which mentions all of the libraries by name:

Here, I'm proposing updating the language about cuGraph on that main API docs page, to clarify that all those libraries are documented in there.

• mentions all the cuGraph libraries by name
• removes references to DGL (https://docs.rapids.ai/notices/rsn0046/)

[netlify]

✅ Deploy Preview for docs-rapids-ai ready!

Name	Link
🔨 Latest commit	8bd4924
🔍 Latest deploy log	https://app.netlify.com/projects/docs-rapids-ai/deploys/689d0818e01e670008a850f3
😎 Deploy Preview	https://deploy-preview-671--docs-rapids-ai.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify project configuration.

[acostadon]

Looks good

[jameslamb]

Thanks!