Create comparable sample messages side by side from each major existing framework

[gvelez17]

can we get a sample message, the same message in a format compatible with

- ActivityStreams
- Solid
- Matrix
- Gun
- Twitter API submission
- other?

with the JSON-LD code of each message in a file in a common directory in this repo?

[AaronGoldman]

http 1.0

POST /greet HTTP/1.0
Referer: http://example.com
Connection: Keep-Alive
User-Agent: Mozilla/3.01
Host: bob.example.com:80
Accept: image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, */*
Content-type: application/x-www-form-urlencoded
Content-length: 42

from=alice&to=bob&string=Hello