docs: add none provider documentation

docs/content/3.providers/none.md

@@ -0,0 +1,34 @@
+---
+title: None
+description: A pass-through provider that returns images without any transformations.
+links:
+  - label: Source
+    icon: i-simple-icons-github
+    to: https://github.com/nuxt/image/blob/main/src/runtime/providers/none.ts
+    size: xs
+---
+
+The `none` provider is a minimal pass-through provider that returns image URLs without applying any transformations or optimizations.
+
+This provider is useful when you want to use Nuxt Image components for consistent markup and loading behavior, but don't need actual image optimization.
+
+## Usage
+
+```ts [nuxt.config.ts]
+export default defineNuxtConfig({
+  image: {
+    provider: 'none'
+  }
+})
+```
+
+## Behavior
+
+When using the `none` provider:
+- No image transformations are applied (resizing, format conversion, etc.)
+- Modifiers are ignored
+- The original image URL is returned as-is
+- All Nuxt Image component features like lazy loading and placeholders still work
+
+This is particularly useful for development, testing, or when your images are already optimized and you just want the component interface.
+