Action documentation for Cpp is incorrect

[edwardalee]

The documentation here:

https://www.lf-lang.org/docs/next/writing-reactors/actions/

is incorrect for Cpp because Cpp doesn't support minDelay, minSpacing and spacing violation policies for actions.

Note that the lack of support for minSpacing will make it much more difficult to implement decentralized coordination when there is bidirectional communication.