Add TPM signature reference

[salrashid123]

Adds an example reference for TPM based signatures

i can also add in pkcs-11 reference included here https://github.com/salrashid123/golang-jwt-pkcs11

[oxisto]

That's very cool!

[salrashid123]

i wrote a couple others but they havn't been tested yet or highly experimental/alpha so i'll defer adding them in

• for ml-dsa: https://github.com/salrashid123/golang-jwt-pqc (currently uses cloudflare's implementation but should eventually use standard go)
• for a generic crypto.Signer https://github.com/salrashid123/golang-jwt-signer
• and the pkcs one from above https://github.com/salrashid123/golang-jwt-pkcs11

(for ref, gcp authentication uses jwt signatures so if the key is in a TPM, its helps w/ some security)

[mfridman]

No objection to adding this one. But we should probably figure out a baseline for adding these.

Maybe this should live in the docs or a separate "community" repository?