fix: add caution

src/content/docs/en/reference/container-reference.mdx

@@ -68,7 +68,11 @@ For each official Astro integration, import and use the `getContainerRenderer()`
 
 For renderer packages outside the `@astrojs` npm org, look in their documentation for `getContainerRenderer()` or a similar function provided.
 
-When using `vite` (`vitest`, Astro integrations, etc.), the renderers are loaded with the function `loadRenderers()` from the virtual module `astro:container`. Outside `vite`, you'll have to load the renderers manually.
+When using `vite` (`vitest`, Astro integrations, etc.), the renderers are loaded with the function `loadRenderers()` from the virtual module `astro:container`.
+
+:::caution
+Outside `vite` or for on-demand usage, you'll have to [load the renderers manually](#adding-a-renderer-manually).
+:::
 
 The following example provides the necessary object to render an Astro component that renders a React component and a Svelte component: