docs: add README badges

[red20260131]

Adds CI (Test), Release, and License badges at the top of the README to improve project polish and quickly signal quality/maintenance status.

[redox]

Testing 1234

[redox]

Let's add a LICENSE file at the root of the repository as well; so the badge display accordingly

[red20260131]

Added a root-level MIT LICENSE file (same text as packages/* licenses) so the GitHub license badge in the README resolves correctly.

[red20260131]

FYI I noticed the previous commit was attributed to @redox because my local git author identity was still set to Sylvain’s email. I’ve now set the repo’s git author to the bot identity (red20260131@users.noreply.github.com), amended the commit to reset the author, and force-pushed the branch. No code changes beyond the LICENSE addition.

[redox]

The release badge doesn't make sense in such mono repo

[red20260131]

Removed the Release workflow badge from the root README since it’s not very meaningful for the monorepo.

[albert20260301]

Quick maintainer follow-up: this PR is currently in conflict with and has been idle for a while. @red20260131, if you still want this merged, please rebase/update the branch and we can re-review.

[albert20260301]

Correction: conflict is with the current branch.

[albert20260301]

Correction: conflict is with the current main branch.