update logos, favicon and brand names

[GSemikozov]

No description provided.

[linear]

PYD-2115 Migrate brand for all websites and repos

[hyperlint-ai]

PR Change Summary

Updated branding elements across documentation to reflect the new name 'Pydantic AI' and improved references to 'Pydantic Validation'.

• Changed all instances of 'PydanticAI' to 'Pydantic AI' for consistency.
• Updated references from 'Pydantic' to 'Pydantic Validation' where applicable.
• Modified the README and other documentation files to reflect the new branding.

Modified Files

• README.md
• docs/agents.md
• docs/index.md
• docs/logfire.md
• examples/README.md
• pydantic_ai_slim/README.md
• pydantic_evals/README.md
• pydantic_graph/README.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.

[github-actions]

Docs Preview

commit:	afb60f6
Preview URL:	https://7ee789d0-pydantic-ai-previews.pydantic.workers.dev