What is the principle of its implementation

kubeedge-counter-demo. There are four .yaml files in the CRD file,For example, kubeedge-counter-model.yaml, what is its function. And the other three. Yaml files? I want understand its principle and create other functions.My English is very poor and hope you will not mind it!

Start by reading the kubeedge-counter-demo example and kubeedge-counter-model.yaml, then identify the other three YAML files in its CRD setup. Trace how the files are used together and document each file's function and the overall implementation principle. Done means a newcomer can understand the example and know how to create another function.

Written by the indexing model from the issue text.