fix(installation): first PowerShell command

ExecutionPolicy to RemoteSigned command was fixed because the old command was getting denied access to change the Execution Policy property

Author: cseltol

README.md

@@ -36,7 +36,7 @@ This will install Rustlings and give you access to the `rustlings` command. Run
 In PowerShell, set `ExecutionPolicy` to `RemoteSigned`:
 
 ```ps
-Set-ExecutionPolicy RemoteSigned
+Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope CurrentUser
 ```
 
 Then, you can run: