Mirgration Guide and update README.md

[EchoEllet]

Just updating the documentation to be more readable, adding a migration guide, and that almost all

but the important change was changing the version number to 8.0.0
which is something we should have done but I hope we don't make any more breaking changes because we don't want the version number to reach 100 in one month

[singerdmx]

I won't be able to publish it until 7 hours later

[EchoEllet]

@singerdmx Wait don't merge yet, I'm getting a warrning

Package validation found the following potential issue:
* Rename the top-level "docs" directory to "doc".
  The Pub layout convention is to use singular directory names.
  Plural names won't be correctly identified by Pub and other tools.
  See https://dart.dev/tools/pub/package-layout.

What do you say?? should we rename the folder from docs to doc to follow the pub convention??

[singerdmx]

Sure

[EchoEllet]

I won't be able to publish it until 7 hours later

Sure

Done, do you know how I can chat with @Jon-Salmon in private??

[singerdmx]

No idea he is probably in Europe?

[EchoEllet]

No idea he is probably in Europe?

I mean private chat using something like Discord, Slack, Telegram etc...

[singerdmx]

No idea

[EchoEllet]

No idea

I think this pull request is ready to merge if you are.
sure we can't publish this yet to pub.dev bu at least the people in GitHub can see the migration guide