Feature request: allow website to add a descriptive text to signing requests

[quochuy]

It is something useful to be able to tell the user why the website requires signing a payload. For example, when using Keychain to login into Steemit. If you upload an image into their post editor, this comes up:

This screen does not tell much.

[shawnpringle]

I would argue against this feature. As it could be a way to get you to sign something you do not want to sign.