Add a simple quickstart tutorial about creating reports.

[widhalmt]

The main idea behind this tutorial is to shed some light on the options available when creating reports.

If you want me to change anything, please let me know and I'll push changes. Maybe I missed something stylewise.

[widhalmt]

ref/NC/702078

[RincewindsHat]

ping

[lippserd]

Implemented proper form element descriptions to avoid having documentation where you have to read what the UI should tell you. See #162.