I wrote a [script](https://github.com/j0lv3r4/dependency-version-updater) to update dependencies recursively in `package.json` files, e.g.:
```
$ node index.js --path="./examples" --dependencies="react=^16.7.0,react-dom=^16.7.0"
```
This PR contains the result against the examples folder.
* [add] example of a progressive rendered app
* [update] remove extra blank line
* [update] fix typo
* [update] more use cases
* [update] example link
* Update README.md
* [update] next.js dependency version
* [update] fix readme typos
