feat: use tag @validatable to mark schema types

src/core/things/Diff.ts

@@ -12,6 +12,7 @@
  * You should have received a copy of the GNU General Public License along with
  * this program. If not, see <https://www.gnu.org/licenses/>.
  */
+import * as jsonpatch from 'json-patch';
 import {SCThingsWithoutDiff} from '../Classes';
 import {SCThing, SCThingMeta, SCThingType} from '../Thing';
 import {SCISO8601Date} from '../types/Time';
@@ -43,6 +44,8 @@ export interface SCDiffWithoutReferences extends SCThing {
 
 /**
  * A diff
+ *
+ * @validatable
  */
 export interface SCDiff extends SCDiffWithoutReferences {
   /**