Clarify "json": "<json of protocol message>" as input for encoding example

[tdiesler]

Is the above attachment content really valid? (i.e. a string value for type json)
If not, Base64 URL Encoded value cannot be right.

didcomm-jvm does not accept it

CrossRef: tdiesler/nessus-didcomm#6

[FabioPinheiro]

There is no attachment above.
Are you talking about something like this?

{ 
  "id":"...",
  "attachments": [
     {"data": {"json":"just a json string"}}
   ]
 }

We are assuming this is a valid message.