Bump z per the releasable-set convention. Ship the Info manual
(make info; make info-emacs fallback). Generate README.md from
README.org via Emacs batch ox-md, with a pre-commit hook and
board screenshots.
Add build.el + pre-commit hook so README.org stays the source and
README.md is regenerated for GitHub/MELPA. Refresh README (screenshots,
Crapette, use-package, new customs). Makefile: readme/hooks/info-emacs
targets; ship README.md.
