README: add badges

Add  badges for CI status and go-report to the README.


Signed-off-by: Michael Adam <[email protected]>

Author: obnoxxx

README.md

@@ -1,6 +1,8 @@
 # go-ceph - Go bindings for Ceph APIs
 
 [![Godoc](http://img.shields.io/badge/godoc-reference-blue.svg?style=flat)](https://godoc.org/github.com/ceph/go-ceph) [![license](http://img.shields.io/badge/license-MIT-red.svg?style=flat)](https://raw.githubusercontent.com/ceph/go-ceph/master/LICENSE)
+[![Build Status](https://github.com/checkmake/checkmake/actions/workflows/ci.yml/badge.svg?branch=main)](https://github.com/ceph/go-ceph/actions)
+[![Go Report Card](https://goreportcard.com/badge/github.com/gontract/gontract)](https://goreportcard.com/report/github.com/ceph/go-ceph)
 
 ## Introduction