md2html: render linked .md via the about view, fix relative base

Links to markdown files now point at /<repo>/about/<path> (rendered
through the about-filter) instead of /<repo>/tree/<path> (raw blob), so
clicking a README link to another .md shows rendered markdown.

Also resolve relative links against the rendered file's own directory:
about-formatting.sh now forwards the filename cgit passes ($1) to
md2html as argv[1], and md2html uses dirname(argv[1]) as the base. This
makes links *inside* a rendered subpage (docs/foo.md -> ./bar.md,
../README.md, images) resolve correctly. Non-markdown files and
directories still go to tree/; images to plain/; about/ links carry no
?h= since the about view renders against the configured readme ref.

0 files changed, 0 insertions, 0 deletions