Replace CircleCI with GitHub actions (zio#143)

* Remove CircleCI

* Configure GitHub workflows

* Update badge

* Configure microsite publishing

* Align tag names

* Downgrade Dotty version

* Reduce lint matrix

* Remove 2.11 from build matrix

* Fix syntax issue

* Factor out benchmarks compilation

* Remove matrix params from lint

* Reduce benchmarks compilation matrix

* Remove Dotty

* Add command aliases

* Include JS to build

* Fix condition

* Fix names

* Split js and jvm

* Remove nvmrc

* Remove prefix

* Unify cache names