Update developers/contributing/index.qmd

Co-authored-by: Penelope Yong <[email protected]>

Author: AoifeHughes

developers/contributing/index.qmd

@@ -58,7 +58,7 @@ Turing uses [JuliaFormatter.jl](https://github.com/domluna/JuliaFormatter.jl) to
 We use version 1 of JuliaFormatter. Install it in your **global Julia environment** (not the project environment, as adding it to the Project.toml would make it invalid):
 
 ```julia
-julia -e 'using Pkg; Pkg.activate(); Pkg.add(name="JuliaFormatter", version="1"); Pkg.pin("JuliaFormatter")'
+julia -e 'using Pkg; Pkg.add(name="JuliaFormatter", version="1"); Pkg.pin("JuliaFormatter")'
 ```
 
 #### Formatting Code