Enhance examples usability

[markbader]

Detailed Description

• Affected library: webknossos

We should have another look over the examples of the webknossos repository. Currently, the assumption is that they are read over the rendered documentation. Therefore, the docstring within the example files is rather short. Users that explore the GitHub Repo might need further explanations within the example python files.

Not all examples can be executed. Examples like announce dataset uploads are partly only described in comments and might be difficult to actually apply for users.