Update README (#2056)
Update README (#2056)

* Update README to use releases-stability URL

Change https://docs.openzeppelin.com/contracts/api-stability to https://docs.openzeppelin.com/contracts/releases-stability (even though it redirects)

* Update README to include CLI as dev env

Add OpenZeppelin CLI to list of development environments

* Update README to use releases-stability URL

Change https://docs.openzeppelin.com/contracts/api-stability to https://docs.openzeppelin.com/contracts/releases-stability (even though it redirects)

OpenZeppelin/openzeppelin-contracts,OpenZeppelin/zeppelin-solidity,OpenZeppelin/openzeppelin-contracts,OpenZeppelin/openzeppelin-contracts,OpenZeppelin/zeppelin-solidity,OpenZeppelin/zep-solidity,OpenZeppelin/zep-solidity