examples: add example to trace golang code

[yunwei37]

Description

This example traces the state switch of goroutines, and prints the corresponding state, goid, pid and tgid.

Next step is adding CI support for it.

This is related to #221 and #213

Type of change

• [ ] Bug fix (non-breaking change which fixes an issue)
• [X] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [X] This change requires a documentation update

How Has This Been Tested?

• [X] locally
• [ ] Test B

[yunwei37]

The next step would be adding CI test support.

[Officeyutong]

The next step would be adding CI test support.

Will CI support be added in this PR?