Some easy fixes for someone wanting to get their feet wet

An individual opened a handful of issues flagging Failure techniques missing references to other techniques.
https://github.com/w3c/wcag/issues/created_by/umut-gultekin

Each of these should be a simple change, and I�d encourage anyone new to the group or wanting to get more involved to pick one (or more) up, read it over to see if you agree, and generate a PR. If you have any questions or issues, feel free to reach out to me or Bruce.

Have a good weekend!

Mike