Update README.md

Author: yebai

README.md

@@ -1,8 +1,8 @@
 # DistributionsAD.jl
 
-![ForwardDiff and Tracker tests](https://github.com/TuringLang/DistributionsAD.jl/workflows/ForwardDiff%20and%20Tracker%20tests/badge.svg?branch=master)
+[![ForwardDiff and Tracker tests](https://github.com/TuringLang/DistributionsAD.jl/workflows/ForwardDiff%20and%20Tracker%20tests/badge.svg?branch=master)](https://github.com/TuringLang/DistributionsAD.jl/actions?query=workflow%3A%22ForwardDiff+and+Tracker+tests%22)
 
-![Zygote tests](https://github.com/TuringLang/DistributionsAD.jl/workflows/Zygote%20tests/badge.svg?branch=master)
+[![Zygote tests](https://github.com/TuringLang/DistributionsAD.jl/workflows/Zygote%20tests/badge.svg?branch=master)](https://github.com/TuringLang/DistributionsAD.jl/actions?query=workflow%3A%22Zygote+tests%22)
 
 [![Coverage Status](https://coveralls.io/repos/github/TuringLang/DistributionsAD.jl/badge.svg?branch=master)](https://coveralls.io/github/TuringLang/DistributionsAD.jl?branch=master)