docs: clarification transformIndexHtml (#8786)

Author: Yash-Singh1

docs/guide/api-plugin.md

@@ -332,7 +332,7 @@ Vite plugins can also provide hooks that serve Vite-specific purposes. These hoo
 - **Type:** `IndexHtmlTransformHook | { enforce?: 'pre' | 'post', transform: IndexHtmlTransformHook }`
 - **Kind:** `async`, `sequential`
 
-  Dedicated hook for transforming `index.html`. The hook receives the current HTML string and a transform context. The context exposes the [`ViteDevServer`](./api-javascript#vitedevserver) instance during dev, and exposes the Rollup output bundle during build.
+  Dedicated hook for transforming HTML entry point files such as `index.html`. The hook receives the current HTML string and a transform context. The context exposes the [`ViteDevServer`](./api-javascript#vitedevserver) instance during dev, and exposes the Rollup output bundle during build.
 
   The hook can be async and can return one of the following: