- Renamed https://github.com/schemedoc/rnrs-pdf to
https://github.com/schemedoc/standards

- Removed https://github.com/schemedoc/rnrs-with-errata which had the
same stuff that the above repo has, but generated less rigorously.

- Should probably merge https://github.com/schemedoc/rnrs-metadata into
the new https://github.com/schemedoc/standards, since both deal with the
TeX files.