Revamp the docs

Fix assets:install command for Docker in composer.json

Use the cached mode for some Docker volumes

Use scanelf to detect runtime deps

Bump deps. Downgrade to Postgres 9.6.

Upgrade Flex

Enable autowiring strict mode and class loader inlining

[client] fixed the package name

Use the API in HTTPS by default to prevent mixed content errors

Feat: add GraphQL in README file

Group Docker steps

Improve the Docker setup

Fix wrong URL