Update Help file to define latency parameters

[Orv]

Is your feature request related to a problem? Please describe.
Add a definition of link latency to the AREDN Help function.

Describe the solution you'd like
Is:
blocked - latency: the link latency is too high to reliably pass data.

Change to:
blocked - latency: the link latency is too high to reliably pass data, where excess latency is defined as a single hop taking over 1 second consistently for about 20 minutes.