docs: README with CI-CD badges

Author: grthomson

readme.md

@@ -1,3 +1,7 @@
 # docker-rust-postgres
 
-A simple Rust server/microservice example for [Docker's Rust Language Guide](https://docs.docker.com/language/rust/).
+[![CI](https://github.com/grthomson/docker-rust-postgres/actions/workflows/main.yaml/badge.svg?branch=main)](https://github.com/grthomson/docker-rust-postgres/actions/workflows/main.yaml)
+[![Docker Pulls](https://img.shields.io/docker/pulls/grthomson/docker-rust-postgres.svg)](https://hub.docker.com/r/grthomson/docker-rust-postgres)
+[![Image Size](https://img.shields.io/docker/image-size/grthomson/docker-rust-postgres/latest)](https://hub.docker.com/r/grthomson/docker-rust-postgres/tags)
+
+Minimal Rust + PostgreSQL microservice using Actix Web. Containerised with Docker; includes Docker Compose and CI to Docker Hub.