Add TODO about replacing known_iids with flags

docs/vst3.md

@@ -4,6 +4,9 @@ TODO: Flesh this out further
 
 TODO: Link to `src/common/serialization/vst3/README.md`
 
+TODO: Mention the new `Ya<Base>::supports()` mechanism for monolithic interfaces
+through multiple inheritance
+
 The VST3 SDK uses an architecture where every concrete object inherits from an
 interface, and every interface inherits from `FUnknown`. `FUnkonwn` offers a
 dynamic casting interface through `queryInterface()` and a reference counting

src/common/serialization/vst3/plugin-factory.h

@@ -54,6 +54,9 @@ class YaPluginFactory : public Steinberg::IPluginFactory3 {
 
         /**
          * The IIDs that the interface we serialized supports.
+         *
+         * TODO: Replace this with a set of boolean flags, just like we're doing
+         *       with the other interfaces.
          */
         std::set<Steinberg::FUID> known_iids;