Add a version badge to README.md (#60)

Author: jishnub

README.md

@@ -3,7 +3,7 @@ A Julia package for representing infinity in all its forms
 
 [![Build Status](https://github.com/JuliaMath/Infinities.jl/workflows/CI/badge.svg)](https://github.com/JuliaMath/Infinities.jl/actions)
 [![codecov](https://codecov.io/gh/JuliaMath/Infinities.jl/branch/master/graph/badge.svg)](https://codecov.io/gh/JuliaMath/Infinities.jl)
-
+[![version](https://juliahub.com/docs/General/Infinities/stable/version.svg)](https://juliahub.com/ui/Packages/General/Infinities)
 
 
 This Julia package is used to represent infinities, including:
@@ -18,4 +18,4 @@ Note that we subtype based on interfaces, rather than strict mathematical defini
 
 ## Similar packages
 
-This package is meant to eventually replace [Infinity.jl](https://github.com/cjdoris/Infinity.jl) and the definitions of `∞` in [InfiniteArrays.jl](https://github.com/JuliaArrays/InfiniteArrays.jl). We do not yet support Infinity.jl's notions of `InfExtendedReal` but we hope to add this soon.
+This package is meant to eventually replace [Infinity.jl](https://github.com/cjdoris/Infinity.jl) and the definitions of `∞` in [InfiniteArrays.jl](https://github.com/JuliaArrays/InfiniteArrays.jl). We do not yet support Infinity.jl's notions of `InfExtendedReal` but we hope to add this soon.