pink! is based on Parity's ink! language and provide some extra functionality to interact with phala's fat contract runtime.
The orignal ink!
contract can run under Phala's fat contract platform without any modifacation. So you can follow Parity's ink!
documentation to get started.
If you want to use fat contract's specific features, such as phala-mq message, HTTP requests, you can use pink_extension
to achieve this. See examples for more detail.