Update repo of Julia library (#4408)

The library has been moved to the `JuliaWeb` org. The previous link redirected to the new location.

Co-authored-by: Lee Dohm <1038121+lee-dohm@users.noreply.github.com>

Author: SaschaMann

content/rest/overview/libraries.md

@@ -80,7 +80,7 @@ Library name | Repository |
 
 Library name | Repository |
 |---|---|
-**GitHub.jl**|[WestleyArgentum/GitHub.jl](https://github.com/WestleyArgentum/GitHub.jl)
+**GitHub.jl**|[JuliaWeb/GitHub.jl](https://github.com/JuliaWeb/GitHub.jl)
 
 ### OCaml