This is not really, of course, the first release, but the first one after some real use and testing picked up a few missing features or bugs, so I consider it ready to use.
This is not a release with binaries (specifically, Qt binaries for joinmarket-qt for Windows and Linux). The existing binaries in the previous release (scroll down the releases page or click here) should still be functional. Binaries will be rebuilt when there is a new major release or when something important changes, subject to the constraints of time.
See the instructions here for how to install for the first time or how to upgrade.
Thanks to @eduard6 for considerable help in testing and edits.