rustic 3.0 released

We have added lots of new features since the last major release and the additional tests will hopefully help me to introduce fewer bugs in the future =) Thanks for the contributions!

Are there release notes on what's changed?

Thanks for the great extension！I used it a lot.

Great timing- just started Rust for a second time last weekend and need to get my Emacs setup.

There are release notes in the minor releases and I thought it doesn't make sense to document the changes again in the major release. But maybe I should mention the most important features again.