Document invocation_defaults

[adorton-adobe]

I can't find any reference to the invocation_defaults config option in the documentation. We need to get it documented as soon as possible.

[adorton-adobe]

I found it at the end of the command parameters page. Don't know why I missed it before. I'm leaving this open because it needs more work - we really ought to thoroughly document all of the possible options that can be specified. Neither this manual section nor the comments in the example config have a sufficient level of detail.

[vossen-adobe]

@adorton-adobe if this is still needed, we can add it to our scope

[adorton-adobe]

Probably belongs in the UST Docs epic. I will add it.