Edit firebaseopensource docs (#327)

* update astro

* test

* adapter -> preset

* change nuxt link to nitro

Author: Yuangwang

docs/astro/README.md

@@ -9,6 +9,7 @@ To use follow these instructions:
 1. Install the `@apphosting/astro-adapter` Astro adapter with the following command in your terminal:
 `npx astro add @apphosting/astro-adapter`
 1. Add the adapter with the standalone rendering mode to your astro.config.* file:
+
 ```js
 import { defineConfig } from 'astro/config';
 import node from '@apphosting/astro-adapter';
@@ -20,6 +21,7 @@ export default defineConfig({
   }),
 });
 ```
+
 1. Push the changes to github and kickoff a new rollout
 
 > **Experimental:** While this adapter was built by Google employees, it is not currently an official Google Cloud product. Support is best-effort only.

docs/nitro/README.md

@@ -1,5 +1,4 @@
-# App Hosting Nitro Adapter
-
+# App Hosting Nitro Preset
 
 Applications powered by Nitro have zero-configuration support for Firebase App Hosting, using the Firebase App Hosting preset. [Learn more in the Nitro documentation](https://nitro.build/deploy/providers/firebase).
 

docs/nuxt/README.md

@@ -1,5 +1,5 @@
 # Nuxt on Firebase App Hosting
 
-Nuxt support on Firebase App Hosting is powered by the [community-supported Nitro preset](https://firebaseopensource.com/projects/FirebaseExtended/firebase-framework-tools::docs::nuxt).
+Nuxt support on Firebase App Hosting is powered by the [community-supported Nitro preset](https://firebaseopensource.com/projects/FirebaseExtended/firebase-framework-tools::docs::nitro).
 
 > **Community-supported:** While built in collaboration with Firebase App Hosting, the Nitro preset is not currently an official Google Cloud product. Support is best-effort only.