doc: update readme

Signed-off-by: William Albertus Dembo <[email protected]>

README.md

@@ -1 +1,53 @@
-# patroni_exporter
+[![CI](https://github.com/gopaytech/patroni_exporter/workflows/Main%20Deployment/badge.svg)][ci]
+[![Go Report Card](https://goreportcard.com/badge/github.com/gopaytech/patroni_exporter)][goreportcard]
+[![License](https://img.shields.io/badge/License-Apache%202.0-blue.svg)][license]
+
+[ci]: https://github.com/gopaytech/patroni_exporter/actions?query=workflow%3A%22Master+Deployment%22+branch%3Amaster
+[goreportcard]: https://goreportcard.com/report/github.com/gopaytech/patroni_exporter
+[license]: https://opensource.org/licenses/Apache-2.0
+
+# Patroni Exporter for Prometheus
+Simple server that scrapes Patroni stats and exports them via HTTP for Prometheus consumption.
+
+## Getting Started
+
+To run it:
+
+```bash
+./patroni_exporter [flags]
+```
+
+Help on flags:
+
+```bash
+./patroni_exporter --help
+```
+
+For more information check the [source code documentation][gdocs].
+
+[gdocs]: http://godoc.org/github.com/gopaytech/patroni_exporter
+
+## Usage
+
+--patroni.host="http://localhost"
+Specify Patroni API URL using the `--patroni.host` flag.
+Specify Patroni API port using the `--patroni.port` flag.
+```bash
+./patroni_exporter --patroni.host="http://localhost" --patroni.port=8008
+```
+
+### Building
+
+```bash
+make build
+```
+
+### Testing
+
+```bash
+make test
+```
+
+## License
+
+Apache License 2.0, see [LICENSE](https://github.com/gopaytech/patroni_exporter/blob/master/LICENSE).