issues/15: change default config path

Signed-off-by: Mark McCormick mark.mccormick@chainguard.dev

Code change for raised issue / change: #15

The application comes with a predefined configuration file path set to config/conf.yaml. While this path can be overridden using the -config= argument during runtime, it brings along certain complexities.

For instance, the Kubernetes manifest examples in this repository are based on the assumption that the root user is running the application, hence they mount the config directory to /root/config. Similarly, when packaging this application, it necessitates knowing in advance which user will run the application in order to determine the appropriate configuration path.

To streamline usability and align with prevalent conventions, especially the Filesystem Hierarchy Standard (FHS) which designates /etc/ as the location for system-wide configuration files, it would be more practical to default to a user-agnostic location. A suggested path for this could be /etc/smarter-device-manager/.