Remove __astro_component from knownEntrypoints (#327)

* Remove __astro_component from knownEntrypoints

* Adds a default site. Otherwise the build throws

* Adds the changeset

.changeset/empty-geese-yawn.md

@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Fixes regression caused by attempting to prebuild an internal dep

packages/astro/snowpack-plugin.cjs

@@ -6,7 +6,7 @@ const transformPromise = import('./dist/compiler/index.js');
 module.exports = (snowpackConfig, { resolvePackageUrl, hmrPort, renderers, astroConfig } = {}) => {
   return {
     name: 'snowpack-astro',
-    knownEntrypoints: ['astro/dist/internal/h.js', 'astro/components/Prism.astro', 'astro/dist/internal/__astro_component.js'],
+    knownEntrypoints: ['astro/dist/internal/h.js', 'astro/components/Prism.astro'],
     resolve: {
       input: ['.astro', '.md'],
       output: ['.js', '.css'],

packages/create-astro/src/templates/blog/astro.config.mjs

@@ -4,7 +4,7 @@ export default {
   // dist: './dist',       // When running `astro build`, path to final static output
   // public: './public',   // A folder of static files Astro will copy to the root. Useful for favicons, images, and other files that don’t need processing.
   buildOptions: {
-    // site: '',           // Your public domain, e.g.: https://my-site.dev/. Used to generate sitemaps and canonical URLs.
+    site: 'http://example.com',           // Your public domain, e.g.: https://my-site.dev/. Used to generate sitemaps and canonical URLs.
     // sitemap: true,      // Generate sitemap (set to "false" to disable)
   },
   devOptions: {