initial import, >900commits predate this

docs/framework/engine/interfaces.md

@@ -0,0 +1,23 @@
+# Default Shipped Interfaces
+
+### Index
+
+* `MM::Services::SceneServiceInterface`
+
+
+## SceneServiceInterface
+
+Not very stable. But I use it all over the place.
+
+It uses [`EnTT`](https://github.com/skypjack/entt).
+
+### interface
+
+Use `.getScene()` to get current `MM::Scene`.
+
+Use `.changeScene(newScene)` to queue `.changeSceneNow(newScene)`.
+
+Use `.changeSceneNow(newScene)` to change currently held `MM::Scene`.
+
+Use `.addSystemToScene(fn)` to add a `MM::System` to the `MM::Scene`.
+