Fixes two issues with the configuration:
- @fu5ha wasn't getting review request due to user name rename.
- Our [Embark Open Source Tool project checker](https://github.com/EmbarkStudios/opensource/tree/main/src) that validates our projects have maintainers assigned categorized this as not fully maintained as didn't have a root owner `*`, @eddyb I made this you right now instead of just for `/crates/`. But we can tweak that going forward also. But this will keep our Slack bot happy
* Make maintainers explicit with CODEOWNERS
Hello!
We're making maintainers explicit. I've guessed the maintainers here, let me know if this is not right. Thanks!
* Update CODEOWNERS
Fix syntax
* Update CODEOWNERS
* Update CODEOWNERS