added more form generator libraries

[bergos]

This PR adds some more form generator libraries.

• Two release date badges show an error message "no releases or repo not found" but the URL should be OK. I guess it may take some time till they get updated.
• form-generator has no release date badge as it is hosted on GitLab, and shields.io doesn't provide badges for it.
• danielbeeke/shacl-form was never released on npm, so there is no badge for it.
• The inactive projects are simple and have a well-structured code base. They could be a good source of inspiration for anyone doing work in that field, and that's why I thought they are worth being listed here.