version 2

[treeben77]

Version 2 of rblx-open-cloud.

• Adds many new APIs including experience restrictions, subscriptions, join requests, memory stores, notifications and more.
• Asynchronous version of the library
• New send_request function and other shortcut functions
• Many breaking changes from v1
• Documentation changes
• The libraries' code style is now black

More information: https://rblx-open-cloud.readthedocs.io/en/v2/guides/v2.html

The current state of version 2 in this pull request does not include:

• Luau Execution and Instance APIs (these have been moved to the engine branch.)
• Legacy Game Internationalization API
• update and create of Creator Store Product API (they are currently broken)

Thanks to the contributions from @LawMixer and @ignaigna!