Activating cfg files in openhab2

What do I have to do with loading cfg files?
Background: I have saved a file hms. cfg in /etc/openhab2/services. When is it loaded by openhab2?

configuration files are loaded instantly or at least when openHAB is (re-) started.

The questions are: What is this file good for? and: Is the name hms. cfg or is the name hms.cfg? The former won’t be loaded at all (wrong suffix), the latter will, if there is a binding named hms binding installed yet.

The filename is hms.cfg and it is for an hms humidity sensor

I’m not aware of a hms binding, is it from openHAB marketplace?