Update installation instructions

README.md

@@ -19,12 +19,7 @@ which also includes tutorials and examples.
 `LumenManufaktur.jl` is not an officially registered Julia package but it's available via
 the [KM3NeT Julia registry](https://git.km3net.de/common/julia-registry). To add
 the KM3NeT Julia registry to your local Julia registry list, follow the
-instructions in its
-[README](https://git.km3net.de/common/julia-registry#adding-the-registry) or simply do
-
-    git clone https://git.km3net.de/common/julia-registry ~/.julia/registries/KM3NeT
-    
-After that, you can add `LumenManufaktur.jl` just like any other Julia package:
+instructions there. After that, you can add `LumenManufaktur.jl` just like any other Julia package:
 
     julia> import Pkg; Pkg.add("LumenManufaktur")