Also remove spaces in `_ A _ ` because that does not show up correctly in a real
markdown renderer, e.g. on GitHub.
Fixes: #467
Signed-off-by: Christophe de Dinechin <christophe@dinechin.org>
Add a link to the [HP Museum of calculators](https://www.hpmuseum.org)
to explain why HP's legacy in that respect is so important.
Add a link to [Paul Graham's site](http://www.paulgraham.com/avg.html)
to explain why having a Lisp-like programming language is useful.
Signed-off-by: Christophe de Dinechin <christophe@dinechin.org>
Improve the on-line help mostly to test some of the features of the help
rendering engine.
Signed-off-by: Christophe de Dinechin <christophe@dinechin.org>
This is distantly derived from the help system I implemented for newRPL, but the
low-memory condition on the DM42 means we try to do everything without
allocating any memory.
Signed-off-by: Christophe de Dinechin <christophe@dinechin.org>
