Fix outdated Nushell completion script

src/System.CommandLine.StaticCompletions/shells/NuShellShellProvider.cs

@@ -18,31 +18,13 @@ public class NushellShellProvider : IShellProvider
 
     private static readonly string _dynamicCompletionScript =
         """
-        # Add the following content to your config.nu file:
-
-        let external_completer = { |spans|
-            {
-                dotnet: { ||
-                    dotnet complete (
-                        $spans | skip 1 | str join " "
-                    ) | lines
-                }
-            } | get $spans.0 | each { || do $in }
+        def "nu-complete dotnet" [context: string] {
+            ^dotnet complete $"($context)" | lines 
         }
 
-        # And then in the config record, find the completions section and add the
-        # external_completer that was defined earlier to external:
-
-        let-env config = {
-            # your options here
-            completions: {
-                # your options here
-                external: {
-                    # your options here
-                    completer: $external_completer # add it here
-                }
-            }
-        }
+        export extern "dotnet" [
+            ...command: string@"nu-complete dotnet"
+        ]
         """;
 
     public string GenerateCompletions(System.CommandLine.Command command) => _dynamicCompletionScript;