example's a path has a error

[summer-boythink]

Describe the bug
When I read example, I noticed an error in line 24 of main.go in the read-file folder. It should be mock/mock.yml, but mock/mock.yaml is used here. But the mock folder does not have this file

To Reproduce
source code

Additional context

I found that some files used mock.yml and some used mock.yaml. So to ensure compatibility, I think I should add a mock.yaml to the mock folder, which is a copy of mock.yml