Enhacement: document rationale

[ciroiriarte]

Hello!, I wonder why was this created instead of proposing the rewrite as guacamole-client 2.0, probably first thing users ask themselves. Might be worth adding that to the README.md

[davekempe]

Gday @ciroiriarte . Thanks for the feedback. Its a reasonable question, the bottom line is we didn't feel that upstream would really be down for a complete clean start on the client. Its Open Source, so everyone is free to choose or do what they want to do. Sometimes you gotta be free to take things in your own direction. I will see what we can add that has some more background rationale in the README for the next release.

[ciroiriarte]

Well, per https://issues.apache.org/jira/plugins/servlet/mobile#issue/GUACAMOLE-1085, they need to heavily rework it either way.