[React ESI](https://github.com/dunglas/react-esi) is a brand new cache library for vanilla React and Next.js applications, that can make highly dynamic applications as fast as static sites by leveraging the open Edge Server Include specification.
https://github.com/dunglas/react-esi
Because this spec is widespread, React ESI natively supports most of the well-known cloud cache providers including Cloudflare Workers, Akamai and Fastly. Of course, React ESI also supports the open source Varnish cache server that you can use in your own infrastructure for free (configuration provided).
This PR shows how to integrate React ESI with Next.js.
* Examples: clarify language around Yarn create & npx
* add missing READMEs and create-next-app usage
* suggest people tag jthegedus in firebase related issues
* add yarn alt instructions
* cerebraljs example readme & fixes
* remove global npm install of create-next-app
* add npx to create-next-app command in examples
* add bash to shell snippets
* add yarn create to next-app command in examples
* fix READMEs named with lowercase
* change READMEs to use UPPERCASE
