Merge open license pages into ONE page

[rebeccawilliams]

Currently, there are several places on Project Open Data to learn about how the licensing field should be filled out:

• https://project-open-data.cio.gov/open-licenses/
• https://project-open-data.cio.gov/license-examples/
• https://project-open-data.cio.gov/licensing-resources/ and, of course,
• the metadata guidance: https://project-open-data.cio.gov/v1.1/schema/ & https://project-open-data.cio.gov/v1.1/schema/#license

We should consolidate this information and there should also be a US Public Domain URL available, possible URLs could be:

• http://www.copyright.gov/title17/92chap1.html#105 (this is my preference, with my motivations being an authoritative permalink)
• http://www.usa.gov/copyright.shtml, or
• a new Project Open Data URL, similar to: https://project-open-data.cio.gov/unknown-license/

This issue is not meant to replace the ongoing licensing discussions on Project Open Data, but to clean up and clarify ASAP to assist agencies in more explicit labeling.

cc @philipashlock @gbinal @jlberryhill

[rebeccawilliams]

Okay, it is not one page, but /open-licenses/ and /license-examples/ are now one page located at: /open-licenses/ see PR #454. More context was added for US Public Domain as well.

[rebeccawilliams]

This was completed with #454 and #456