Docker: local/compose doesn't exist

[nelgin]

In the docker instructions, we're told to create local/compose/memory-settings.yml to change the pgsql memory settings.

The local directory exists but compose doesn't. You only find this out by editing the file in vi and then trying to save and it fails.

To solve: Either create local/compose in git and instruct it to create empty directories when cloning

or

Tell the user to mkdir local/compose before they continue.

This is more of an annoyance of having to go back and do a step then anything else.