Add Chisel Scala CLI template and automation (#3186) (#3194)

This adds a new Chisel template for using Chisel with Scala CLI, and
adds some automation for uploading versions of this template on tagged
releases (or workflow dispatch).

(cherry picked from commit 20246185

)

Co-authored-by: Jack Koenig <koenig@sifive.com>
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>