Runs poetry relax after poetry add succeeds. Parses options from add and sends them to relax to try to keep the same scope as an add command. For example, --dry-run is passed through to prevent relaxing when something wasn't actually added and --group is passed through to prevent relaxing outside of the group an item is added to.

Requires opt-in with configuration

[tool.poetry-relax]
relax_on_add = true

Closes #5

Needs tests