Add Configuration for Docker Dev Environment

[betsyecastro]

Adds Docker configuration for docker-dev containerized services stack integration.

Includes:

• localdev-shared-services network setup to connect to Redis and MySQL services.
• nginx-proxy network setup for proxy server.
• .docker/ directory with Apache and PHP configurations.
• Xdebug and ImageMagick extensions in the PHP container for local development.
• Storage symlink using container path instead of local machine path.

WIP:

• Browsershot for PDF downloads.
• Currently working on mail catcher setup.

[betsyecastro]

Mailpit working.