docs: fix Resources module API docs naming conventions and broken links

- Rename constructor/destructor files to follow template spec:
  - ctor.md → constructor.md, dtor.md → destructor.md (audioclip)
  - texture_constructor.md → constructor.md, texture_destructor.md → destructor.md (texture)
  - material-loader-constructor.md → constructor.md, material-loader-destructor.md → destructor.md

- Create missing constructor/destructor docs:
  - audio-loader: constructor.md, destructor.md
  - texture-loader: constructor.md, destructor.md

- Fix broken links to ResourceManager:
  - shader-loader/index.md
  - material-loader/index.md

- Remove duplicate folders (keep hyphenated versions):
  - Delete shaderloader/ (keep shader-loader/)
  - Delete resourcepackage/ (keep resource-package/)
  - Merge textureimportsettings/ into texture-import-settings/

- Rename audio-loader method files:
  - canload.md → can-load.md
  - getdefaultsettings.md → get-default-settings.md
  - getsupportedextensions.md → get-supported-extensions.md

- Update overview pages with proper method links and constructor/destructor entries

docs/api/resources/shader-loader/index.md

@@ -56,4 +56,4 @@ if (result.IsSuccess()) {
 
 - [Shader](../shader/shader.md)
 - [IResourceLoader](../iloader/iloader.md)
-- [ResourceManager](../resource-manager/resource-manager.md)
+- [ResourceManager](../resourcemanager/resourcemanager.md)