correct comment

Author: tbrowder

doc/Language/modules-core.pod6

@@ -9,7 +9,7 @@ list of them along with a link to their source code.
 
 The following modules are known to used by external programs and modules.
 
-=item L<CompUnit::Repository::Staging|https://github.com/rakudo/rakudo/lib/CompUnit/Repository/Staging.pm>    Used by installers such as C<zef>
+=item L<CompUnit::Repository::Staging|https://github.com/rakudo/rakudo/lib/CompUnit/Repository/Staging.pm>    Used by distribution build tools
 =item L<NativeCall|https://github.com/rakudo/rakudo/lib/NativeCall.pm6>    Used by many external modules
 =item L<NativeCall::Types|https://github.com/rakudo/rakudo/lib/NativeCall/Types.pm6>    Used by C<NativeCall>
 =item L<NativeCall::Compiler::GNU|https://github.com/rakudo/rakudo/lib/NativeCall/Compiler/GNU.pm6>    Used by C<NativeCall>