fix(examples/with-docker): add npm comment for yarn build (#35040)
fix(examples/with-docker): add npm comment for yarn build (#35040)

There was an `npm` equivalent for `yarn install` (`npm ci`) but not one for `yarn build`. I've added `npm run build` as a commented out option.

## Documentation / Examples

- [x] Make sure the linting passes by running `yarn lint`

azukaru/next.js,azukaru/next.js,JeromeFitz/next.js,azukaru/next.js,JeromeFitz/next.js,azukaru/next.js,JeromeFitz/next.js,JeromeFitz/next.js