added columns for tracking created/updated

abstracto-application/templating/templating-interface/src/main/java/dev/sheldan/abstracto/templating/model/database/Template.java

@@ -42,6 +42,22 @@ public class Template {
     @Getter
     private Instant lastModified;
 
+    @Column(name = "created")
+    private Instant created;
+
+    @PrePersist
+    private void onInsert() {
+        this.created = Instant.now();
+    }
+
+    @Column(name = "updated")
+    private Instant updated;
+
+    @PreUpdate
+    private void onUpdate() {
+        this.updated = Instant.now();
+    }
+
     @Override
     public boolean equals(Object o) {
         if (this == o) return true;