tag 3 documentation missing

[andrews441]

I'm taking the opentelemetry class in Udemy and trying to type in all of the changes between lessons. The 'docs/adding-metrics.md' file is missing a few pieces from the lecture: sleep function and query parameters

[habmic]

I think it is there: https://github.com/habmic/opentelemetry-101/blob/main/docs/adding-metrics.md