[Playground] [Task]: Configure browser caching so that a new deployed version is loaded

### What needs to happen?

Yesterday we deployed the frontend version that removed the Apache Beam summit banner.
Yet when I navigated to https://play.beam.apache.org I saw the old version with the banner.
I had to press Ctrl-F5 to load the new deployed vesion.

There must be a way to:

- Configure the cache so it asks if a new version of index file is available.
- Use hash of the content in all static file names, so that their names are changed with the content and so they are not cached.

Or some other way for smarter caching.

### Issue Priority

Priority: 3

### Issue Component

Component: beam-playground