added minimal astro adapter + improved the example

app/src/adapter/astro/astro.adapter.ts

@@ -0,0 +1,21 @@
+import { Api, type ApiOptions } from "bknd";
+
+type TAstro = {
+   request: {
+      url: string;
+      headers: Headers;
+   };
+};
+
+export type Options = {
+   mode?: "static" | "dynamic";
+} & Omit<ApiOptions, "host"> & {
+      host?: string;
+   };
+
+export function getApi(Astro: TAstro, options: Options = { mode: "static" }) {
+   return new Api({
+      host: new URL(Astro.request.url).origin,
+      headers: options.mode === "dynamic" ? Astro.request.headers : undefined
+   });
+}