Configuration is expected to be placed in one of hammer's configuration directories for plugins:
/etc/hammer/cli.modules.d/~/.hammer/cli.modules.d/./.config/cli.modules.d/(config dir in CWD)
If you install hammer_cli_foreman from source you'll have to copy the config file manually
from config/foreman.yml.
See our sample config file that lists all available configuration options with descriptions.