change texinfo `coding: us-ascii' to utf-8?

[Mark Polesky]

All the doc files' header comments contain

  coding: utf-8

except macros.itexi and most of the contributor/ folder,
which have

  coding: us-ascii

instead.  I assume that's an oversight, and it's okay to
push the attached patch?

Thanks.
- Mark

0001-Doc-us-ascii-utf-8-in-texinfo-headers.patch
Description: Text Data