Clarify limits of licensing w.r.t generated output of tools

[amykyta3]

in https://github.com/orgs/SystemRDL/discussions/184, @CodeStillBroken requested:

Can your team make a clear and unambiguous statement on the PeakRDL website ( e.g. in the licensing section ) clarifying what license, if any, applies to the output generated by running the PeakRDL tools covered by GPL v3? My understanding is that the output of the program is not governed by the terms of the program's license. If that is the case, it would be helpful to clearly state that the customer owns all rights to the outputs generated by the PeakRDL tools on your website :)

Add a similar statement to what is described in regblock docs to the general PeakRDL docs.
Will need to clarify that this exemption only covers core PeakRDL components, and 3rd-party plugins may be licensed differently.

Alternatively, consider switching away from GPL and move to the more FOSS hardware-friendly Apache license, as it is less likely to spook the lawyers.