* Add sp() output descriptor format for BIP352 Silent Payments
* Update headers and remove space after comma in descriptors
* Add label ranges with examples
* Update with assigned number and adjust preamble for BIP3
* BIP392: Add table entry to README
* Add two argument key expression form and remove birthday and label arguments
* Add BIP392 sp() descriptor to BIP380 script expressions table
* Add sp() descriptor to BIP390 allowed expressions and add musig() example to BIP392
* Add changelog and version header to BIP390
