permanent URLs for different versions of the policy

[npdoty]

It would be useful if EFF could host not only the current most recent version of the EFF DNT policy, but also permanent, version-specific URLs for different iterations of the policy, e.g. https://www.eff.org/dnt-policy/1.0.txt

I see that raw.githubusercontent.com URLs are currently referenced for different versions of the policy, but I'm not sure if those URLs are expected or guaranteed to be stable; if it's the EFF policy, I would personally prefer to point to something at eff.org. (On the other hand, if they are being guaranteed to be permanent, that would be a good thing to document as well.)

[michael-oneill]

I referred to the EFF Policy in the compliance property in this (unofficial) guide https://trackingprotection.github.io/Implementation/DNTGuide/#the-compliance-array
which is in a public GitHub repo here https://github.com/TrackingProtection/Implementation/blob/master/DNTGuide/index.html if anyone wants to comment or send a PR