Add copyright headers to the .str files

The .str script files don't have copyright headers, but I think they
should.  I used the same dates that chew.c uses, which I think makes
sense because these are inputs to chew.

2023-02-07  Tom Tromey  <tom@tromey.com>

	* doc/doc.str, doc/proto.str: Add copyright header.


3 files changed