Docs init for proxies

[poppyseedDev]

add a section somewhere in the docs on how to initialize the fhevmconfig and gateway config for proxies

[poppyseedDev]

An example of usage:
https://github.com/zama-ai/dapps/blob/154b351ce03994c69a6fa48c6a4bf97e724ee6bd/hardhat/contracts/fheWordle/FHEWordleFactory.sol#L62-L64
https://github.com/zama-ai/dapps/blob/154b351ce03994c69a6fa48c6a4bf97e724ee6bd/hardhat/contracts/fheWordle/FHEWordle.sol#L75-L77

The abstract contract doesn’t work in a proxy obviously because in this case constructor must be replaced by an initializer. So dev must use TFHE.setFHEVM in his custom initializer