register 0.3.1

[KlausC]

@JuliaRegistrator register

[JuliaRegistrator]

Registration pull request created: JuliaRegistries/General/56301

After the above pull request is merged, it is recommended that a tag is created on this repository for the registered package version.

This will be done automatically if the Julia TagBot GitHub Action is installed, or can be done manually through the github interface, or via:

git tag -a v0.3.1 -m "<description of version>" 2b6027c126b90f61bbad4ea230a34367522c3e52
git push origin v0.3.1