[TASK] List the ProxyAdmin address for each network

[alainncls]

While the main README file lists the contract addresses on all supported networks, it doesn't contain the ProxyAdmin addresses for these contracts.

We need to add this address for all supported network, in order to facilitate the transition to a better ownership management (via a Safe wallet).

This address needs to be fetched in the events around the initial deployment of the contracts, on each network.