* Add jext-axe package and introduce a11y testing
Automated a11y testing is NOT comprehensive. We cannot expect this to
even scratch the surface of potential a11y issues.
However, we can expect to find a percentage of issues that are currently
flying under the radar. Adopting some automation around a11y testing
also allows us to use CI to find a11y regressions -- which should be
really handy.
I've never really used Jest before, and Preact seems to make it a little
more complicated, but as far as I can tell, this is a decent way to add
at least some minor automated a11y testing.
* Add doc about automated a11y tests
* Correct installation documentation
* Add stylized titles
* Add some changes to the getting started documentation
* Add changes for the backend guide
* Add changes for the design guide
* Add testing / Q&A guide improvements
* Minor fixes to contributing docs
* More improvements to the general doc
* Improvements for frontend guide
