Clean up package.json files in the `examples` directory:
- Add `private: true`
- Remove `version` (because they are irrelevant for packages that are not meant to be published)
- Remove `name` (because they are optional for packages that are not meant to be published, and when someone clones an example, they often rename it and the property becomes stale)
- Remove `author`
- Remove `description`
- Remove `license`
Also remove `with-dynamic-app-layout` example completely, since it does the same as `layout-component` (https://github.com/vercel/next.js/pull/27121#discussion_r668178408).
## Documentation / Examples
- [x] Make sure the linting passes
[With next 11 requiring react 17](https://nextjs.org/blog/next-11#upgrade-guide), most of the examples
need to be updated, so the following snippet updated all the examples to
a compatible react version.
```bash
cd examples/
fd -g 'package.json' | xargs sed -r -i 's/"react": ".*"/"react": "^17.0.2"/
fd -g 'package.json' | xargs sed -r -i 's/"react-dom": ".*"/"react-dom": "^17.0.2"/'
# exclude experimental react version
git checkout with-reason-relay/package.json
```
r? @lfades
cc @timothyis @dayhaysoos @ChrisBrownie55
* Add [use-shopping-cart](https://github.com/dayhaysoos/use-shopping-cart) example to stripe sample
* Refactor how we instantiate Stripe across the different pages with a `getStripe` singleton pattern.
- Update to latest stripe-node version and pin the exact version so the Types won't go out of sync
- Add the env var changes for next 9.4.4 (https://nextjs.org/blog/next-9-4#new-environment-variables-support)
- Remove `next.config.js` as no longer needed.
- Add the Deploy to Vercel button