docs: plugins

doc/content/docs/plugins.mdx

@@ -130,5 +130,41 @@ const { data, error } = await $fetch("https://jsonplaceholder.typicode.com/path"
     You can also pass a `prefix` to the `createSchema` function to prefix all the routes.
 </Callout>
 
+### Get options
+
+The `getOptions` function allows you to define additional options that can be passed to the fetch function. This is useful when you want to pass options to the plugins that are not part of the `BetterFetchPlugin` interface.
+
+```ts twoslash title="fetch.ts"
+import { createFetch, createSchema, BetterFetchPlugin } from "@better-fetch/fetch";
+import { z } from "zod";
+
+const plugin = {
+    id: "my-plugin",
+    name: "My Plugin",
+    getOptions() {
+        return z.object({
+            onUploadProgress: z.function().args(z.object({
+                loaded: z.number(),
+                total: z.number(),
+            })),
+        });
+    },
+} satisfies BetterFetchPlugin;
+
+const $fetch = createFetch({
+    baseUrl: "https://jsonplaceholder.typicode.com",
+    plugins: [plugin],
+});
+
+const { data, error } = await $fetch("https://jsonplaceholder.typicode.com/path", {
+    onUploadProgress({
+        loaded,
+        total,
+    }) {
+        console.log(`Uploaded ${loaded} of ${total} bytes`);
+    },
+});
+```
+
 ### Properties
 <AutoTypeTable path="./lib/better-fetch-options.ts" name="BetterFetchPlugin" />