https://github.com/kiegroup/drools/pull/4495#issuecomment-1175252899

> as suggested by @evacchi, it is true that with drools 8 we want to promote mainly the paradigm based on rule units and oopath discussed in this commit, but we still also want to fully support the "old" drl style. I believe we need a new chapter in our documentation discussing it, at least as a general introduction and in the parts and use cases where it diverges in a relevant way from rule units.