update packaging

[mathematicalmichael]

update pyscaffold version, update workflows for new packaging procedures.

try fully migrating to pyproject.toml (but ... I do like development installations)

[mathematicalmichael]

pyscaffold version not updated but the workflows are.

[mathematicalmichael]

• don't migrate to rst files
• do include docs this time around during upgrade with pyscaffold
• different homepage on docs than the readme