RDF/PHP Specification

Raw, unfinshed PR in the light of #204
I would be okay with that, if you replace LICENSE.md as well with just a link :) - however I only say so because I assume you won't do that. Just to give a picture.

Generally if a license is used within the repository, the license text has to be given. Links to licenses in general have the problem that you take responsibility for a document that you can not control. In this case the Creative Commons webserver. Links to CC licenses in specific are only applicabl/suggested use where having the license text itself would be burdensom, e.g. putting it into every image of a website via EXIF metadata or similar.

This is not the case with the repository.

If you have a problem with the location of the file (within the root it's clear what applies at a forst glance), a better variant would be to append it to the existing LICENSE.md file and put a little text above it explaining to which part the following license applies (as it's only for that appendix part). Then it's even more clear and you also do central book/housekeeping.