docs: add badges

Signed-off-by: Gustavo Inacio <[email protected]>

Author: gusinacio

README.md

@@ -1,5 +1,12 @@
 # indexer-rs
 
+[![Build Status](https://github.com/graphprotocol/indexer-rs/actions/workflows/containers.yml/badge.svg)](https://github.com/graphprotocol/indexer-rs/actions)
+[![Coverage Status](https://coveralls.io/repos/github/graphprotocol/indexer-rs/badge.svg?branch=main)](https://coveralls.io/github/graphprotocol/indexer-rs?branch=main)
+[![License](https://img.shields.io/github/license/graphprotocol/indexer-rs)](https://github.com/graphprotocol/indexer-rs/blob/main/LICENSE)
+[![Contributing](https://img.shields.io/badge/contributions-welcome-brightgreen.svg)](./CONTRIBUTORS.md)
+[![GitHub Release](https://img.shields.io/github/v/release/graphprotocol/indexer-rs?filter=indexer-service-rs-*)](https://github.com/graphprotocol/indexer-rs/releases?q=indexer-service-rs)
+[![GitHub Release](https://img.shields.io/github/v/release/graphprotocol/indexer-rs?filter=indexer-tap-agent-*)](https://github.com/graphprotocol/indexer-rs/releases?q=indexer-tap-agent)
+
 A Rust implementation for The Graph 
 [indexer-service-ts](https://github.com/graphprotocol/indexer/tree/main/packages/indexer-service) 
 to provide subgraph service as an Indexer,