README.md: add badges

Author: lpenz

README.md

@@ -1,2 +1,9 @@
+[![marketplace](https://img.shields.io/badge/marketplace-rust--coverage-blue?logo=github)](https://github.com/marketplace/actions/rust-coverage)
+[![CI](https://github.com/lpenz/ghaction-rust-coverage/actions/workflows/ci.yml/badge.svg)](https://github.com/lpenz/ghaction-rust-coverage/actions/workflows/ci.yml)
+[![github](https://img.shields.io/github/v/release/lpenz/ghaction-rust-coverage?include_prereleases&label=release&logo=github)](https://github.com/lpenz/ghaction-rust-coverage/releases)
+[![docker](https://img.shields.io/docker/v/lpenz/ghaction-rust-coverage?label=release&logo=docker&sort=semver)](https://hub.docker.com/repository/docker/lpenz/ghaction-rust-coverage)
+
 # ghaction-rust-coverage
+
 Docker github action for source-based rust coverage
+