update integration testing doc

[dheyay]

Why is this needed?

This PR updates the integration testing document to current commands for testing the pro client.

Test Steps

Checklist

• [ ] I have updated or added any unit tests accordingly
• [ ] I have updated or added any integration tests accordingly
• [ ] Changes here need to be documented, and this was done in:

Does this PR require extra reviews?

• [ ] Yes
• [ ] No

[dheyay]

@orndorffgrant @lucasmoura This might need to be updated for the following sections:

• Iterating locally
• Optimizing total run time of integration tests with snapshots

Please feel free to leave comments for specific changes if these sections have to be updated. Thanks!