What's Changed
* Add Angular Material Card component by richard-to in https://github.com/google/mesop/pull/1082
* Consistent type hints for Optional by Jemeljanov in https://github.com/google/mesop/pull/1087
* Fix typo in card component doc by richard-to in https://github.com/google/mesop/pull/1090
* Add expansion panel component. by richard-to in https://github.com/google/mesop/pull/1089
* fix card_header.py docstring & remove security announcement by wwwillchen in https://github.com/google/mesop/pull/1095
* Send experiment settings on initial page load by wwwillchen in https://github.com/google/mesop/pull/1093
* Fix clearing query params when navigating by wwwillchen in https://github.com/google/mesop/pull/1097
* Migrate print calls to logging by wwwillchen in https://github.com/google/mesop/pull/1083
* Runs onload handler for browser navigations (backwards and forwards) by wwwillchen in https://github.com/google/mesop/pull/1101
* Bump to v0.12.9 by wwwillchen in https://github.com/google/mesop/pull/1103
New Contributors
* Jemeljanov made their first contribution in https://github.com/google/mesop/pull/1087
**Full Changelog**: https://github.com/google/mesop/compare/v0.12.8...v0.12.9