css: Smaller preformatted block font on mobile.
articles/(re)sources: Start preformatted blocks on the same line.

To avoid an extra line of white space.
articles / sources: Use spaces instead of tabs in preformatted blocks.

Since tabs don’t show well on mobile, 4-space indentation is more compact.
documents: Remove XHTML conformance section.

It contained font tags, yuch.
css: Responsive design for mobile.
css: Formatting.
Remove two remaining (broken) map bullet references.
css: Remove the toc class.

Doesn’t seem to do anything.
css: Remove width from h1.

It’s a block element so already has the full width?
css: Remove hiding of second menu layer.

Since we removed it in 6503cfad2b7d.
Remove "msxasm" id from some bodies.

No idea what purpose it had being there.
Replace the map bullet list item icon with a text marker.

The list icon doesn’t work very well on mobile (looks too small).
content: Standard Content-Type header capitalisation.
content: Always include the HTML stylesheet link tag.

Since without it Firefox displays a flash of unstyled content.
(And without the <?xml-stylesheet?> Chrome does.)
Convert all line endings from Windows (CRLF) to *nix (LF).
images: Remove no longer used firefox promo images.
tracker: Remove old and unused analytics script.
hgignore: Ignore local todo directory, and also ignore macOS .DS_Store files.
main: Remove directory, move files to root.
planned: Remove list of planned articles.

Woefully outdated, and not referenced.