Encourage CC0 for non-governmental works

The framework includes the following:

> Project documentation for works that are not of the United States Government should unambiguously declare the license under which the project is distributed (e.g, General Public License (GPL), MIT License (MIT)) and that any code publicly posted in association with the project (e.g., pull requests, code comments) must be licensed under the same terms. The most common license are GNU and MIT opensource.org.

As an initial matter, it's unclear whether this is referring to works by government contractors or open-source projects that are used by the government. If it's the latter, than the framework should clarify that and include an additional discussion of work by government contractors.

If it's the former, this documentation requirement is a good one, and suggesting an open-source license like GPL or MIT for non-governmental works is even better. However, CC0 is not limited to governments and could also be applied by government contractors. As such development would be funded by the government, it would make sense (and provide consistency) to release it to the public domain in the same manner as "official" government works.