Rename repository

[bdeneux]

Since proto file is no longer hosted on this repository and instead, provided by the Buf registry (#54); Since this repository is here to generate package containing okp4d grpc client, cosmos-sdk grpc client and maybe more later (cosmwasm, ...), the current repository name : okp4-cosmos-proto doesn't seems to be the good name for that now.

I suggest to rename the repository with one of the following suggestions and open to discussion and propositions :

• okp4/okp4-client
• okp4/okp4-grpc-client
• okp4/cosmos-grpc-client
• okp4/cosmos-client
• okp4/grpc-client

(in bold my favorite 😛)