Add examples + e2e in each example

[aralroca]

| examples
  | counter-with-preact
  | counter-with-next
  | pokedex-with-next
  ...

With a simple example (counter for example):

• with Next.js: test hydration, saving initial store inside getServerSideProps. Test multi pages sharing the same store.
• with Preact
• with React Native
• with React 18 server components
• with graphql
• with ES modules

More complicated examples:

• Pokedex (@danielart idea)