The "Build with Rollup" documentation is broken

Nobody has claimed this yet.

### Which package(s) are affected?

Lit Core (lit / lit-html / lit-element / reactive-element)

### Description

Trying to follow the instructions for [building-with-rollup](https://lit.dev/docs/tools/production/#building-with-rollup) triggers multiple errors:

1. "While loading the Rollup configuration from "rollup.config.js", Node tried to require an ES module from a CommonJS file"
Solution: Rename `rollup.config.js` to `rollup.config.mjs`

2. "The requested module '@web/rollup-plugin-html' does not provide an export named 'default'"
[Solution](https://github.com/modernweb-dev/web/issues/1415):
`import { rollupPluginHTML as html } from "@web/rollup-plugin-html";`

3. The requested module '@rollup/plugin-terser' does not provide an export named 'terser'
[Solution](https://github.com/rollup/plugins/issues/1397):
`import terser from '@rollup/plugin-terser';`

4. TypeError: minifyHTML is not a function
[Solution](https://github.com/asyncLiz/rollup-plugin-minify-html-literals/issues/24):
`import pkgMinifyHTML from 'rollup-plugin-minify-html-literals';`
`const minifyHTML = pkgMinifyHTML.default`

### Reproduction

Follow the instructions at [building-with-rollup](https://lit.dev/docs/tools/production/#building-with-rollup)

### Workaround

See above

### Is this a regression?

No or unsure. This never worked, or I haven't tried before.

### Affected versions

2.x

### Browser/OS/Node environment

node v20.11.0
npm 10.2.4

Open the building-with-rollup section of the Lit documentation and compare its rollup.config.js example with the reported Node, @web/rollup-plugin-html, @rollup/plugin-terser, and rollup-plugin-minify-html-literals errors. Reproduce the instructions with Node v20.11.0 and npm 10.2.4, then update the documented configuration so the build completes without those errors.

Written by the indexing model from the issue text.