improved astro adapter (serving api) + added documentation

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

@@ -1,10 +1,8 @@
 import { Api, type ApiOptions } from "bknd";
+import { App, type CreateAppConfig } from "bknd";
 
 type TAstro = {
-   request: {
-      url: string;
-      headers: Headers;
-   };
+   request: Request;
 };
 
 export type Options = {
@@ -19,3 +17,15 @@ export function getApi(Astro: TAstro, options: Options = { mode: "static" }) {
       headers: options.mode === "dynamic" ? Astro.request.headers : undefined
    });
 }
+
+let app: App;
+export function serve(config: CreateAppConfig) {
+   return async (args: TAstro) => {
+      if (!app) {
+         app = App.create(config);
+
+         await app.build();
+      }
+      return app.fetch(args.request);
+   };
+}