- Allow help files to use the ".md" suffix, and move changelog/whatsnew
to use them.
- When files end with ".md", the "help" program attempts to highlight
them. This involves:
- Colour code blocks with a lightGrey background.
- Replace lists to use bullet points instead of "-"/"*".
- Colours headings yellow.
The implementation of this is a bit janky because a) I wrote this and
b) we need to run this step before text wrapping, but preserve
colours and section positions over wrapping (thanks to Jack for
getting this working).
- Add section navigation to the help viewer, with left/right to move to
the next/previous section.
Closes#569
d71bf225cc