Normalize baseURLs and better document possible values

When putting a slash at the end of the baseURL parameter, the generated urls in the ConfluencePageClass objects contain double slashes. The parameter ought to be normalized so one doesn't need to think too much about which value is expected.

The examples are a bit lacking too, they should contain an example with a particle like /wiki or /docs, so one knows better what to set as value.

The ConfluencePageClass url also unconditionally has a /wiki/ particle, which is incorrect.