Submit BCR-2020-005 As BIP

I think there is a lot of benefit in keeping the development community as unified as possible. I am very glad that a UR standard is being made, and it seems from the development and this discussion here (https://github.com/BlockchainCommons/Airgapped-Wallet-Community/discussions/26) that most HWW developers are on board.

However, PSBT's are not just received/generated by HWWs, and I believe the traditional standards process should be adhered to, and that this should be submitted to bitcoin-dev for feedback from the wider bitcoin community for a BIP.

Please see discussion here: https://github.com/BlockchainCommons/Airgapped-Wallet-Community/issues/4#issuecomment-722829242

This is the link to BCR-2020-005: https://github.com/BlockchainCommons/Research/blob/master/papers/bcr-2020-005-ur.md

And the link to the UR reference implementation in C++: https://github.com/BlockchainCommons/bc-ur

Thank you