Add testable examples to `pdata` module

[mx-psi]

Add testable examples to https://pkg.go.dev/go.opentelemetry.io/collector/pdata.

There's a lot of things that would benefit from examples here, I suggest to start with a single type and add examples for it

[minimAluminiumalism]

@mx-psi I'd like to work on this issue. Can you assign it to me?

[mx-psi]

Sure, Damien assigned it to you :) Please start small so we can give you feedback without you investing too much effort

[codeboten]

I think this issue can be marked as complete with #13244, please reopen if that's not the case