By default, MobX 6 and later require that you use `actions` to make changes to the state, otherwise, it issues a warning in the console, because the `hydrate` method of the `store.js` class hasn't been declared an action, you can see this warning if you try to load pages that use hydration (ssg, ssr).
This pull request fixes that.

More info about the behavior:
https://mobx.js.org/actions.html#disabling-mandatory-actions-

upgrade mobx dependencies for with-mobx example and make all necessary code changes as per https://mobx.js.org/migrating-from-4-or-5.html

addresses #17809 

The method initializeStore is only being used locally by useStore.
By having this exported I initially thought the consumer would have to call this as setup globally and then call useStore as well for each consuming component.

Downloading the sample I saw it's only useStore that is being used by the consuming app and this could be made clear by not exporting initializeStore.

* fix: with-mobx

* refactor: up link

* refactor: npm run prettier-fix

* refactor: server side render

* Updated store implementation and pages

* Updated readme
Co-authored-by: Nwangcheng <wangcheng@deepblueai.com>
Co-authored-by: NLuis Alvarez <luis@zeit.co>

* Updated with-custom-reverse-proxy

* Updated readme of with-env-from-next-config-js

* Updated the kea example

* Updated with-mobx

* Updated with-mobx readme

* Updated the with-mobx-react-lite example

* Update `packages/`

* Update examples

* Update tests

* Update bench

* Update top level files

* Fix build

* trigger

* Add prettier for examples directory

* Fix files

* Fix linting

* Add prettier script in case it has to be ran again

I spent far too much time fiddling with this example project before realizing it contained a bug in the store initialization logic and it was a bit more complex than it needed to be.

* The custom server was not needed
* The store-initialization did effectively the same thing twice for no reason
* And wrapping MyApp component in a HOC was wholly unnecessary indirection

My changes are split into four discrete commits for clarity.

in flavor of https://github.com/zeit/next.js/pull/4377

* Adds mobx example

* Fix coding style to match JS Standard

* Removes unecessary link

* Update README.md

* Update README.md

* Change next version from beta to ^2.0.0-beta

* Assigns the store to a local var

* Adds navigation in the example

* Removes unecessary imports

* Fix coding style to match JS Standard

* Fix Clock import