Feature suggestion: Share Basic with attached signature

[o-techie]

Add the possibility to export basic share as attached signature like:

-----BEGIN PGP SIGNED MESSAGE-----
Hash: [HASH]

[FILENAME] was last modified at [DATE] It has a SHA-256 hash of [HASH]

This proof is signed by PGP key 0x716989eff974fa58
-----BEGIN PGP SIGNATURE-----

[BASE64 SIGNATURE]
-----END PGP SIGNATURE-----

[n8fr8]

Possibly! The goal of basic was to fit inside of a text message (for when there is no internet), but we may already be beyond that.