Added documentation for darkroom-image-loaded event

content/lua.api.manual/events/darkroom-image-loaded.md

@@ -0,0 +1,27 @@
+---
+title: darkroom-image-loaded
+id: darkroom-image-loaded
+weight: 15
+draft: false
+author: "people"
+---
+
+`event`
+
+This event is triggered whenever an image is loaded in darkroom view
+
+# darkroom-image-loaded.callback
+
+```
+function(
+  event : string,
+  image : types.dt_lua_image_t
+)
+```
+
+* **event** - _string_ - The name of the event that triggered the callback.
+* **image** - _[types.dt_lua_image_t](../types/dt_lua_image_t)_ - The image loaded into darkroom view
+
+# darkroom-image-loaded.extra registration parameters
+
+This event has no extra registration parameters.