Improve documentation on new features

[lukasniemeier-zalando]

Looking at the new features that have been introduced in the last 3 versions IMO it's worth the improve the documentation. For example the TokenVerifier should be documented.

[hjacobs]

👍 for documentation 📖

[sina-golesorkhi]

It would be nice to add more JavaDocs in general. It is not always clear what the class and method parameters are supposed to do.

[lasomethingsomething]

@lukasniemeier-zalando @sina-golesorkhi @harti2006 @jbellmann @hjacobs Hi all, going to work with Andre and Joerg on the docs tomorrow to make them clearer. Please put any other requests/missing details here.

[lasomethingsomething]

@lukasniemeier-zalando @sina-golesorkhi @hjacobs Hey, so @harti2006 and @jbellmann and I did do the promised docs work. If you guys are still interested and using this project, can you take a look and press further with suggestions? cc @duergner