Merge https://github.com/google/adk-python/pull/1143
## Summary
Added a DeepWiki badge to the README.md file to provide users with easy access to interactive documentation that stays automatically updated.
## Changes Made
- Added DeepWiki badge to the existing badge section in README.md
- Badge links to: https://deepwiki.com/google/adk-python
## What is DeepWiki?
DeepWiki provides up-to-date documentation you can talk to, for every repository in the world. By adding this badge to our repository, we help users find and interact with documentation more easily. Users can ask questions about the codebase and get contextual answers based on the latest repository content.
The documentation is automatically updated weekly, ensuring that users always have access to the most current information about the ADK codebase, including new features, API changes, and code examples that reflect the latest development progress.
COPYBARA_INTEGRATE_REVIEW=https://github.com/google/adk-python/pull/1143 from takashikik:add-deepwiki-badge d9b8bc676c9fe2e94c7b3f0ae49814452e45b5f9
PiperOrigin-RevId: 769273276
