Docker-Compose and WordPress with php.ini file.

This is a refactored docker-compose file following the structure of the official exampele from https://docs.docker.com/compose/wordpress/.

It addresses the issue of how to increase the upload limit and how to change php.ini variables within the container. See docker-library/wordpress#10.

1. Create and configure a .env file. (See .env-example for an example)
2. Adapt the wordpress/php.ini file to your liking.
3. Make sure Docker is running and build the containers by running docker-compose build
4. Start the container by running docker-compose up -d. You should now be able to bring up wordpress by browsing to localhost:8000