Fix link syntax

Author: GoneUp

README.md

@@ -1,6 +1,6 @@
 # go-pingen-sdk
 ![Build Status](https://github.com/goneup/go-pingen-sdk/workflows/release/badge.svg)
-![Go Report Card](https://goreportcard.com/badge/github.com/goneup/go-pingen-sdk)](https://goreportcard.com/report/github.com/goneup/go-pingen-sdk)
+[![Go Report Card](https://goreportcard.com/badge/github.com/goneup/go-pingen-sdk)](https://goreportcard.com/report/github.com/goneup/go-pingen-sdk)
 ![GitHub release (latest by date)](https://img.shields.io/github/v/release/goneup/go-pingen-sdk?style=plastic)