Adds GraphQL

[Naramsim]

Hi,

this PR brings in the ability to spin up a GraphQL server based on our PostgresQL tables. Currently the setup works only with the docker-compose installation. It's based on Hasura Engine (https://github.com/hasura/graphql-engine).

An hasura engine is started along pokeapi with docker compose. When pokeapi is built, Hasura can be started with make and all the metadata contained in the folder /graphql will be loaded in. In few seconds Hasura reads the pokeapi DB and exposes a custom private GraphiQL instance on port 8080. For more info browse this PR's README.

4 GraphQL examples are also present in /graphql/examples.

---

Some README sections were moved.

[phalt]

These changes look good to me. Do we promote it wider at the beta phase to test it out? Would be good to get some load testing done. I can use the twitter account to let people know.

[Naramsim]

Great Paul, I'll merge the PR. We could add something on Twitter and also add a banner on the official website.

[pokeapi-machine-user]

A PokeAPI/api-data refresh has started. In 45 minutes the staging branch of PokeAPI/api-data will be pushed with the new generated data.

The staging branch will be deployed in our staging environment and you will be able to review the entire API.

A Pull Request (master<-staging) will be also created at PokeAPI/api-data and assigned to the PokeAPI Core team to be reviewed. If approved and merged new data will soon be available worldwide at pokeapi.co.