Fixed paths for config file copying

If a user were to copy and paste the commands they fail since the config
directory is not at the filesystem root.
Fixed migration command to be more correct, even if not copy-pastable
Added missing password argument for the mysql migration command
Trimmed trailing whitespace
Added instruction for creating database before trying to set up the tables
Removed some subheadings from install instructions

The instructions had two random headings that didn't make sense.

CLONE PROJECT

1. do stuff

INSTALL COMPOSER DEPENDENCIES

2. command to install composer dependencies

3+ something completely unrelated to composer or dependencies
Merge branch 'wording-fix'