Adding the 2023 IETF Trust license

[ounsworth]

I stick the text of the IETF Trust Legal Provisions into all my I-D repos. I assume that's appropriate for both this template repo as well as any I-D repos created from it.

(I see that your workflows automatically create a different LICENSE.md file, so maybe there's a more workflow-y way to generate this rather than committing the file? Setting the copyright year automatically at the time that the template is used would be nifty.)

[martinthomson]

I would rather not include a license here, though I have been convinced in the past to add a license file elsewhere as part of setup.

The advantage to having a license as part of the setup phase is that it can more readily be updated. See https://github.com/martinthomson/i-d-template/blob/main/template/CONTRIBUTING.md

[ounsworth]

I agree that the license is mentioned in the CONTRIBUTING.md, but it would be better if it was in the place that github expected it to be.

I guess the question is whether the license should apply to projects cloned from this template, or also to the template repo itself. What's your reason for not including a license?