docs: Add Component, GameObject, TransformComponent and Scene API documentation

- Add Component class documentation with lifecycle methods
- Add GameObject class documentation with component system
- Add TransformComponent documentation with transform methods
- Add Scene class documentation with GameObject management
- Add SceneManager singleton documentation with scene loading
- Update components.md overview with all component classes
- Update main.md navigation with Scene module

docs/api/components/transform-component/get-child.md

@@ -0,0 +1,32 @@
+# GetChild
+
+Get a child transform by index.
+
+## Syntax
+
+```cpp
+TransformComponent* GetChild(size_t index) const;
+```
+
+## Parameters
+
+- `index` - The index of the child transform (0-based).
+
+## Returns
+
+Returns a pointer to the child transform at the specified index, or `nullptr` if the index is out of range.
+
+## See Also
+
+- [GetChildCount](get-child-count)
+
+## Examples
+
+```cpp
+void Example(TransformComponent* transform) {
+    TransformComponent* firstChild = transform->GetChild(0);
+    if (firstChild) {
+        XC_LOG_INFO("First child: {}", firstChild->GetName());
+    }
+}
+```