Fix broken link to documentation
Rename newleaf folder for sorting reasons
Add filters documentation
Organise documentation into folders if applicable
Differentiate Between User and System Service Manager

Currently the documentation only shows how to talk to the system service
manager, which doesn't work for user services, so show both usages in
the docs.
Also make clear that root privileges are needed for the interaction with
the system service manager.
Add system services; split nginx to a separate file
Add submitting a patchset documentation
Add list of URL parameters
Add configuration documentation
Add updating documentation (to installing files)
Add API documentation
Add installing documentation