more detailed instructions for export from US

README

@@ -173,7 +173,9 @@
  textual explanation of what your patch does.
 
  Note: For legal reasons, contributions from the US can be accepted only
- if a copy of the patch is sent to crypt@bxa.doc.gov
+ if a TSA notification and a copy of the patch is sent to crypt@bis.doc.gov;
+ see http://www.bis.doc.gov/Encryption/PubAvailEncSourceCodeNofify.html [sic]
+ and http://w3.access.gpo.gov/bis/ear/pdf/740.pdf (EAR Section 740.13(e)).
 
  The preferred format for changes is "diff -u" output. You might
  generate it like this: