Add explicit documentation license statement

[jeromekelleher]

Gigascience requested that we add an explicit statement of the license for documentation. This is the best way of doing this I could think of. We get this at the footer of every documentation page:

(The screenshot is a bit too big, just look at the bottom of the image! I also realised I missed a "the" after making this initially and have fixed in the PR)

I toyed briefly with using CC-BY or something to try and prevent LLMs from eating our docs, but then realised that we actively want our documentation to be incorporated into AI models (and anyway, it would almost certainly be ignored by scrapers).

@tomwhite @benjeffery, do you agree with this approach?

[coveralls]

coverage: 98.811% (+0.04%) from 98.772%
when pulling 469893d on jeromekelleher:license-docs
into fb4a6a5 on sgkit-dev:main.

[tomwhite]

I toyed briefly with using CC-BY or something to try and prevent LLMs from eating our docs, but then realised that we actively want our documentation to be incorporated into AI models

We do, but CC-BY would give attribution, which would be a good thing, wouldn't it? See e.g. https://opensource.google/documentation/reference/creating/documentation.

Any thoughts here @hammer?

[hammer]

I’m fine with CC-BY or even CC0 https://creativecommons.org/publicdomain/zero/1.0/

[benjeffery]

Makes sense to me - agree with the licence you've picked

[jeromekelleher]

We do, but CC-BY would give attribution, which would be a good thing, wouldn't it?

I agree it would be nice to get attribution, but I don't think anyone building an LLM would actually abide by that, and I don't foresee ever having the motivation of wanting to actually make someone do this. So let's just put this stuff in the public domain and let whoever do whatever they want with it.