Add recommendation of where the support files should be located

[hhorak]

This is based on a practice that we've been following for the RHSCL container images and which proofed to be working very well. e.g.: https://github.com/sclorg/mysql-container/tree/master/5.7

[eliskasl]

@hhorak looks good, just fix the markdown please and I'll merge it.

[eliskasl]

@hhorak ping :)