Add migration notice to documentation and README

[tuler]

Summary

This PR adds migration notices to the project documentation and README to inform users that this repository has been moved to the deroll project and is now published under the @deroll/cm package.

Changes

• Added a warning admonition to the documentation homepage (docs/pages/index.mdx) directing users to the new repository location and package
• Added a notice to the README.md file with the same migration information

Details

The notices inform users to:

• File issues in the new deroll repository
• Follow development in the new location
• Use the new @deroll/cm npm package

This helps ensure users are aware of the project relocation and directs them to the correct location for ongoing support and development.

https://claude.ai/code/session_01XJB2yWomofyrRYTZGQT2B9

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Latest commit: fd10dca

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