[Documentation]: All docs should load namespaces

[rly]

What would you like changed or added to the documentation and why?

Until we make load_namespaces=True the default setting, all docs should demonstrate load_namespaces=True by default.

I cannot see a common use case where we would not want to load namespaces.

Do you have any interest in helping write or edit the documentation?

Yes.

Code of Conduct

• I agree to follow this project's Code of Conduct
• Have you checked the Contributing document?
• Have you ensured this change was not already requested?

[stephprince]

load_namespaces=True is now the default NWBHDF5IO setting since #1748 so I think this no longer applies.