Xdebug enable doesn't work with custom nginx file

[JamelleG]

Issue:

When using the command

wf2 xdebug enable

From the m2 recipe along with a custom nginx file doesn't take affect.

Proposed solution:

• Add a configuration file to control the arg_debug flag. As an example the file could be xdebug.conf
• This file would determine whether it's enabled regardless of whether the flag is passed or not.
• Add documentation to include this file when using custom nginx files.

But open to suggestions on this one.