structure_template_feature is incompatible

The latest release has broken structures that worked since ~1.17.

When loading an addon, with structures that previously worked, I see an error that "structure_template_feature" is considered internal and thus not compatible with this version of the game.

1. This feature is publicly documented If it's truly internal, the documentation should not reference it.

2. If this feature is truly meant for internal use only, then which of the new feature types should we use to replace it? Looking at the documentation, none of the other feature types seem suitable for a traditional structure (i.e. house/etc).