Replace Legacy Badge

Update the legacy badge for greenkeeper with a NPM JS badge and a Unit Test badge.

README.md

@@ -1,6 +1,6 @@
 # ts-auto-guard
 
-[![Greenkeeper badge](https://badges.greenkeeper.io/usabilityhub/ts-auto-guard.svg)](https://greenkeeper.io/)
+![NPM Version](https://img.shields.io/npm/v/ts-auto-guard?link=https%3A%2F%2Fwww.npmjs.com%2Fpackage%2Fts-auto-guard) [![Test](https://github.com/rhys-vdw/ts-auto-guard/actions/workflows/test.yml/badge.svg)](https://github.com/rhys-vdw/ts-auto-guard/actions/workflows/test.yml)
 
 > Generate type guard functions from TypeScript interfaces
 
@@ -206,4 +206,3 @@ export function isPerson(obj: unknown): obj is Person {
   )
 }
 ```
-