Investigate class docstring missing module name in example

[microbit-matt-hillsdon]

Mark raised that this docstring is missing the module name so don't just work for users:

On investigation, the stub has the full audio.play. What's going on here?

In addition to the apparent defect, for this autocompletion scenario it would be useful for all class docstrings (particularly enum type classes) to have an example in the same style as the function docstrings. I think this will work already if we just change the docs.