create badge (#635)

* create badge

* change position of jet in badge

* Update README.md

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Co-authored-by: Shuhei Kadowaki <40514306+aviatesk@users.noreply.github.com>

README.md

@@ -3,6 +3,7 @@
 [![](https://img.shields.io/badge/docs-latest-blue.svg)](https://aviatesk.github.io/JET.jl/dev/)
 [![](https://github.com/aviatesk/JET.jl/actions/workflows/ci.yml/badge.svg)](https://github.com/aviatesk/JET.jl/actions/workflows/ci.yml)
 [![](https://codecov.io/gh/aviatesk/JET.jl/branch/master/graph/badge.svg)](https://codecov.io/gh/aviatesk/JET.jl)
+[![](https://img.shields.io/badge/%F0%9F%9B%A9%EF%B8%8F_tested_with-JET.jl-233f9a)](https://github.com/aviatesk/JET.jl)
 
 JET employs Julia's type inference system to detect potential bugs and type instabilities.