astro 1.0.0-beta.53

#3685 3d554fdb Thanks @bholmesdev! - Fix PostCSS config not applied to Svelte component by default
#3665 9a813268 Thanks @matthewp! - Allow TypeScript inside script tags

This makes it so that you can use TypeScript inside of script tags like so:
```
<script>
  interface Person {
    name: string;
  }

  const person: Person = {
    name: 'Astro',
  };

  console.log(person);
</script>
```
Note that the the VSCode extension does not currently support this, however.
#3633 921d9a27 Thanks @FredKSchott! - Fix a bug with astro add react adding a too-complex semver to your package.json
#3676 85c33751 Thanks @matthewp! - Allow specifying entryFileNames for client JS