Update deepsymmetry.org host key for user guide deployment.

Update build for GitHub Actions backwards incompatible change

Update dependencies.

Support negative latencies.

Fix close parenthesis location

Provide updated guidance

Fix range in port validation error message.

Update change log [skip ci]

Use new versions of beat-link and beat-carabiner

Update to newer libraries.

Fix snapshot detection. [skip ci]

Add Getting Help section, Zulip credit.

Fix startup user guide link [skip ci]

Ignore PayPal link failures in htmlcheck

Add htmltest configurtion file