Udpate README for async and tlsrpt support

README

@@ -7,7 +7,9 @@ http://hewgill.com/pydkim/
 INTRODUCTION
 
 dkimpy is a library that implements DKIM (DomainKeys Identified Mail) email
-signing and verification.
+signing and verification.  Basic DKIM requirements are defined in RFC 6376:
+
+https://tools.ietf.org/html/rfc6376
 
 VERSION
 
@@ -24,13 +26,13 @@ needed for asyncio.
 
  - Python 2.x >= 2.7, or Python 3.x >= 3.5.  Recent versions have not been
    tested on python < 2.7 or python3 < 3.5, but may still work on python2.6
-   and python 3.1 - 3.3.
+   and python 3.1 - 3.4.
  - dnspython or pydns. dnspython is preferred if both are present and
    installed to satisfy the DNS module requirement if neither are installed.
  - argparse.  Standard library in python2.7 and later.
  - authres.  Needed for ARC.
  - PyNaCl.  Needed for use of ed25519 capability.
- - aiodns.  Needed for asycnio (Required python3.5 or later)
+ - aiodns.  Needed for asycnio (Requires python3.5 or later)
 
 INSTALLATION
 
@@ -145,7 +147,7 @@ code 0 if the signature verifies successfully. Otherwise, it returns with exit
 code 1. 
 
 As of version 0.6.0, dkimpy provides experimental support for ARC (Authenticated
-Received Chain):
+Received Chain).  See RFC 8617 for the current version of ARC:
 
 https://tools.ietf.org/html/rfc8617
 
@@ -154,6 +156,38 @@ arc_sign and arc_verify functions as well as an ARC class.
 
 Both DKIM ed25519 and ARC are now considered stable (no longer experimantal).
 
+ASYNC SUPPORT
+
+As of version 1.0, an alternative to dkim.verify for use in an async
+environment is provied.  It requires aiodns, https://pypi.org/project/aiodns/.
+Here is a simple example of dkim.verify_async usage:
+
+>>> sys.stdin = sys.stdin.detach()
+>>>
+>>> async def main():
+>>>     res = await dkim.verify_async(message)
+>>>     return res
+>>>
+>>> if __name__ == "__main__":
+>>>     res = asyncio.run(main())
+
+This feature requires python3.5 or newer.
+
+As of version 1.0, the RFC 8460 tlsrpt service type is supported:
+
+https://tools.ietf.org/html/rfc8460
+
+A non-tlsrpt signed with a key record with s=tlsrpt won't verify.  Since the
+service type (s=) is optional in the DKIM public key record, it is not
+required by RFC 8460.  When checking for a tlsrpt signature, set the tlsrpt=
+flag when verifying the signature:
+
+>>> res = dkim.verify(smessage, tlsrpt='strict')
+
+If tlsrpt='strict', only public key records with s=tlsrpt will be considered
+valid.  If set to tlsrpt=True, the service type is not required, but other
+RFC 8460 requirements are applied.
+
 FEEDBACK
 
 Bug reports may be submitted to the bug tracker for the dkimpy project on