19efc01aec6b0d8750413fa1b721e04aaecf8f73 Add PSBT documentation (Pieter Wuille)
Pull request description:
This is just some initial text to get going; other contributions welcome.
I'd like to include other workflows, such as hardware wallets and (manual) coinjoins. However, the former will in practice require PSBT interfaces for existing hardware devices, and the second can really use some extra RPCs first.
Tree-SHA512: 951e475e31bb2ea9ab5d84d139b8bc436153ad035185f00ad1d56afc0c6f7c4de8176a785a6d0c38bb3fd9cbf318e513e1a032e83e1da99ded5d43a36f9cbc60
