message: README: Update title
diff: -# Graph Protocol Indexer Components
  +# Graph Protocol Indexer Components (Private)
  ![CI](https://github.com/graphprotocol/indexer/workflows/CI/badge.svg)
  [![Docker Image: Indexer Service](https://github.com/graphprotocol/indexer/workflows/Indexer%20Service%20Image/badge.svg)](https://hub.docker.com/r/graphprotocol/indexer-service)
  