Release undocumented API features behind a feature flag #3081
Description
Summary
Make undocumented but working API features accessible under a preview=True flag, for example
What is the feature request for?
The core library
The Problem
Stuff like a user's profile theme colors are currently undocumented but working on the official API. This makes bringing these features into Pycord "risky", as they could break or be removed at any point.
The Ideal Solution
These features can be hidden under a feature flag. @Soheab suggested a @preview decorator that is applied to any experimental / undocumented (by Discord) properties or functions which makes them show a warning / exception, and which also modifies their docstring to contain an explanation of how to use them. Using these properties and methods is made possible by passing something like preview=True to the client, which signals to the user that the functions accessible via this should be used with care.
The Current Solution
No response
Additional Context
Some stuff this could be used for includes a user's profile theme colors or their banner color if no banner is set