This adds a bit of CSS to set a sans-serif font (preferably Arial),
as that looks a bit nicer than the default. It also adds a viewport
directive and sets a font size that make mobile devices happier.
Also, standardize on UTF-8 (some pages specified cp1252).
This adds TEACH.SAMPLE and CHARSET.MAP to the tutorial sample disk.
The former shows some font and style changes, the latter has a
table with all 256 characters.