update simple stack query package name

Author: bholmesdev

www/src/content/docs/query.mdx

@@ -32,7 +32,7 @@ If you are using an older version of Simple Query, [check the GitHub releases](h
 Simple Query is an Astro integration. We recommend installing with the `astro add` CLI:
 
 ```bash
-astro add simple-stack-query
+astro add @simplestack/query
 ```
 
 To install this integration manually, follow the [manual installation instructions](https://docs.astro.build/en/guides/integrations-guide/#manual-installation)