Migration Guide for 2.8.x -> 3.0.0

[ThijmenL98]

As a developer it would be nice to have a migration guide from version 2.8.x to 3.0.0 as a lot has been changed.

For example:

• Intercom, Company & User class/object creation functions have been removed, what is the new way
• Custom Attributes on said class/objects have changed/been removed
• Probably much more

[fern-support]

You're absolutely right! We are actually currently in the process of adding support for the legacy sdk as a submodule along with a migration guide in the README. This should be landing sometime in the next couple weeks.