Update docker-compose.yml with frequently used environment variables …

[iVegas]

…for php container

[iVegas]

closes #507
closes #508

[csandanov]

Hi, why set log level to 0? We probably do need to change the default to 3

[iVegas]

The php image already uses the default log level value if xdebug is enabled.
In case I want to change the log level I'll uncomment the line and set a different log level.
Unless xdebux connection is not configured by a developer default value is enough to help establish it. Once IDE listens to the web server correctly logging is no longer needed.
So frequently used values for xdebug logger level are 3 or 0. That`s why I provided a different to the default value for the xdebug logging level.

[csandanov]

Unless xdebux connection is not configured by a developer default value is enough to help establish it.

The current default log level is 7 which information, I guess it makes sense to change it to 3 (warnings), change it directly in the wodby/php image, not just here through env vars

[iVegas]

Added related PR wodby/php#184