public ModelAssembler discoverModels() {
        return addDiscoveredModels(ModelDiscovery.findModels());
    }
Discovers models by merging in all models returns by {@link ModelDiscovery}
manifests using the thread context {@code ClassLoader}.

@return Returns the model assembler.
smithy-model/src/main/java/software/amazon/smithy/model/loader/ModelAssembler.java