feat: add initial People Playground mod development kit

extracted_wiki_content/internalReference/backgrounditemloaderstatusbehaviour.txt

@@ -0,0 +1,37 @@
+URL: https://wiki.studiominus.nl/internalReference/BackgroundItemLoaderStatusBehaviour.html
+Title: People Playground Modding - BackgroundItemLoaderStatusBehaviour
+==================================================
+
+public class BackgroundItemLoaderStatusBehaviour
+Inherits MonoBehaviour
+Behaviour that controls the little loading box in the bottom center of the screen
+Fields
+public Sprite DefaultThumbnailSprite
+The fallback sprite for when there is no sprite given
+
+public TextMeshProUGUI TitleMesh
+[Space]
+A reference to the text mesh for the title
+
+public TextMeshProUGUI StateMesh
+A reference to the text mesh for the status
+
+public Image ThumbnailImage
+A reference to the image element for the thumbnail
+
+Properties
+public static BackgroundItemLoaderStatusBehaviour Instance { get; private set; }
+The main instance of this singleton
+
+Methods
+public void SetDisplayData(string name, Sprite thumbnail)
+Set the current title and sprite to display
+
+public static void SetDisplayState(string state)
+Set the current status to display
+
+public static void Show(string name, Sprite thumbnail)
+Show the loading box
+
+public static void Hide()
+Hide the loading box