Support for matching JWK private key

[AnthonyPoschen]

Is your feature request related to a problem? Please describe.
discovered JWK's in source code wrote a custom rule to match them

Describe the solution you'd like
my custom rule added for everyone else as a default rule.

Describe alternatives you've considered
None. if it isn't worth it close the ticket.

Additional context

[[rules]]
    id    = "JWK private keys"
    regex = '''\{(?:\\"|")kty(?:\\"|"):(?:\\"|")(.*?)(?:\\"|"),(?:\\"|")n(?:\\"|"):(?:\\"|")(.*?)(?:\\"|"),(?:\\"|")e(?:\\"|"):(?:\\"|")(.*?)(?:\\"|"),(?:\\"|")d(?:\\"|"):(?:\\"|")(.*?)(?:\\"|"),(?:\\"|")p(?:\\"|"):(?:\\"|")(.*?)(?:\\"|"),(?:\\"|")q(?:\\"|"):(?:\\"|")(.*?)(?:\\"|"),(?:\\"|")dp(?:\\"|"):(?:\\"|")(.*?)(?:\\"|"),(?:\\"|")dq(?:\\"|"):(?:\\"|")(.*?)(?:\\"|"),(?:\\"|")qi(?:\\"|"):(?:\\"|")(.*?)(?:\\"|")\}'''

https://phpseclib.com/docs/rsa-keys#private-keys-3

cc @zricethezav