Support field fileData (direct file URL) for Gemini models

[vricciardulli]

This PR addresses the feature request described in issue #1134

The implementation proposed here is straightforward: add a FileUrl class that can be used in user prompts in the same way that DocumentUrl and similar are used.

The main downside I see with this approach is that this is only supported by Gemini models on Vertex AI and, in minor measure, by GLA-Gemini models, while the FileUrl can in principle be used with any model (and would lead to a RuntimeError exceptions being raised in some models).

[hyperlint-ai]

PR Change Summary

Added support for the FileUrl class to enable direct file URL input for Gemini models on Vertex AI, enhancing the input capabilities for users.

• Introduced the FileUrl class for direct file URL input.
• Updated documentation to include instructions for using FileUrl with Gemini models.
• Clarified that only Gemini models on Vertex AI support this feature.

Modified Files

• docs/input.md

---

How can I customize these reviews?

Check out the Hyperlint AI Reviewer docs for more information on how to customize the review.

If you just want to ignore it on this PR, you can add the hyperlint-ignore label to the PR. Future changes won't trigger a Hyperlint review.

Note specifically for link checks, we only check the first 30 links in a file and we cache the results for several hours (for instance, if you just added a page, you might experience this). Our recommendation is to add hyperlint-ignore to the PR to ignore the link check for this PR.

What is Hyperlint?

Hyperlint is an AI agent that helps you write, edit, and maintain your documentation.

Learn more about the Hyperlint AI reviewer and the checks that we can run on your documentation.

[vricciardulli]

Also allowed FileUrl to be passed to GLA-Gemini models, as it is supported as the docs show. Although that documentation does not provide much information and PDF files don't seem to be supported. YouTube URLs seem to be supported by the GLA.