Fix Github Actions badge and add new GPU backends (#669)

Author: christiangnrd

README.md

@@ -9,7 +9,7 @@
 [buildkite-img]: https://badge.buildkite.com/512eb7dd35ca5b427ddf3240e2b4b3022f0c4f9925f1bdafa8.svg?branch=master
 [buildkite-url]: https://buildkite.com/julialang/gpucompiler-dot-jl
 
-[gha-img]: https://github.com/JuliaGPU/GPUCompiler.jl/workflows/CI/badge.svg?branch=master
+[gha-img]: https://github.com/JuliaGPU/GPUCompiler.jl/actions/workflows/Test.yml/badge.svg?branch=master
 [gha-url]: https://github.com/JuliaGPU/GPUCompiler.jl/actions?query=workflow%3ACI
 
 [pkgeval-img]: https://juliaci.github.io/NanosoldierReports/pkgeval_badges/G/GPUCompiler.svg
@@ -21,4 +21,4 @@
 This package offers reusable compiler infrastructure and tooling for
 implementing GPU compilers in Julia. **It is not intended for end users!**
 Instead, you should use one of the packages that builds on GPUCompiler.jl, such
-as [CUDA.jl](https://github.com/JuliaGPU/CUDA.jl) or [AMDGPU.jl](https://github.com/JuliaGPU/AMDGPU.jl).
+as [CUDA.jl](https://github.com/JuliaGPU/CUDA.jl), [AMDGPU.jl](https://github.com/JuliaGPU/AMDGPU.jl), [Metal.jl](https://github.com/JuliaGPU/Metal.jl), [oneAPI.jl](https://github.com/JuliaGPU/oneAPI.jl), or [OpenCL.jl](https://github.com/JuliaGPU/OpenCL.jl).