Merge pull request 'feature/add-respin' (#91) from feature/add-respin into develop

Reviewed-on: #91
Reviewed-by: Pham Huynh Duc Huy <huy.pham@mercurystudiogroup.com>

docs/03-setup-special-feature/03-respin.md

@@ -1,7 +1,72 @@
 ---
 sidebar_position: 3
 ---
+# Respin Feature
 
-# Respin
+### Overview
+**Respin** is a bonus mechanic in slot games that allows players to re-spin selected reels without restarting the full spin.  
+It typically triggers after a specific in-game condition (e.g. near-win or bonus hit) and enhances player engagement.
 
-> To be added
+> Respin ends when the respin counter reaches **zero**.
+
+```mermaid
+stateDiagram-v2
+    Spin --> SpinEnd 
+    Spin --> Condition_Trigger : case Special
+
+    SpinEnd --> Condition_Trigger : No Win
+    SpinEnd --> Win
+    Win --> Win_Complete : case normal
+    Win_Complete --> Condition_Trigger
+    Condition_Trigger --> Trigger_Respin
+    ```
+---
+
+### Main Scene
+
+#### Triggering Respin
+- Triggered by game logic after a win or specific pattern.
+- Node setup required in Scene graph.
+
+| Action | Image |
+|--------|-------|
+| Create Respin Trigger Node | ![Trigger](./img/respin/node-trigger-in-scenes.png) |
+
+#### Respin Feature
+1. **Trigger Respin**  
+   ![Trigger](./img/respin/trigger.png)
+
+2. **Re-trigger Respin**  
+   ![Retrigger](./img/respin/retrigger.png)
+
+3. **Respin Win**  
+   This step handles the outcome evaluation after a respin.  
+   Its implementation depends on the specific game design and may be optional in some games.
+
+---
+
+### Handle Event
+
+#### Respin Event Handling
+- Override class: `hyper-gaming-server-handler`
+
+| Process | Image |
+|---------|-------|
+| Listen for event: `"respins" | ![Script](./img/respin/handle-event.png) |
+| Trigger Data from Server | ![Trigger](./img/respin/handle-trigger.png) |
+| Re-trigger Data | ![Retrigger](./img/respin/handle-retrigger.png) |
+
+---
+
+### Feature Management
+
+#### Feature Class Setup
+- Create `feature-respin` class extending `feature-game`
+- Responsibilities:
+  - Manage respin panel UI
+  - Handle trigger & retrigger logic
+
+| Action | Image |
+|--------|-------|
+| Script: Feature Panel | ![Script](./img/respin/script-feature-respin.png) |
+| Script: Trigger/Retrigger | ![Trigger](./img/respin/script-trigger-retrigger.png) |