Add QuestSystem addon (#311)

README.md

@@ -214,6 +214,7 @@ See [Vivraan/godot-lang-support](https://github.com/Vivraan/godot-lang-support).
 - [Input Helper](https://github.com/nathanhoad/godot_input_helper) - A helper for detecting input devices and remapping controls (Godot 3.x, 4.x).
 - [obs-websocket-gd](https://github.com/you-win/obs-websocket-gd) - Script and editor plugin to control Open Broadcaster Software from Godot via obs-websocket (Godot 3.x).
 - [Orchestrator](https://github.com/Vahera/godot-orchestrator) - Dialog and visual-scripting subsystem for 2D and 3D games (Godot 4.x).
+- [QuestSystem](https://github.com/ShomyKohai/quest-system) - A simple and extensible quest manager and creator (Godot 4.x).
 - [Ridiculous Coding](https://github.com/jotson/ridiculous_coding) - Makes your coding experience in Godot 1000× more ridiculous (Godot 3.x).
 - [Scene Manager](https://github.com/glass-brick/Scene-Manager) - Make nice and customizable scene transitions in one line of code (Godot 3.x, 4.0.alpha).
 - [Scrolling Background](https://github.com/dploeger/godot-scrollingbackground) - A scrolling background node (Godot 2.1,3.x).