[trn]

I have updated the documentation/README to provide background and rationale, and elaborated a bit on other comments.

OpenBSD's vi (and OpenVi) differ distinctly from both Nvi (https://repo.or.cz/nvi.git) and Nvi2 (https://github.com/lichray/nvi2) in terms of features and support, having diverged 25 years previously, where the OpenBSD/OpenVi branch has embraced minimalism and simplicity.

For a quick and non-scientific comparison, C source lines of code (as counted by tokei) for the various distributions of the Nvi-derived editors:

Nvi - 62,315 SLOC

Nvi2 - 32,408 SLOC

OpenVi - 40,065 SLOC

And looking ONLY at the core editor functionality and bundled regular expression engines:

Nvi - 35,874 SLOC

Nvi2 - 32,019 SLOC

OpenVi - 31,678 SLOC