Add arq42 documentation

[fabiodmota]

Added arq42 doc , upgraded versions
Documentation approved by [email protected]

[SebastianBezold]

Hi @fabiodmota,
for transparency reasons, can you please ask Alexander to do his review in the open. As a comment to this PR for example.
I can also see, that you bumped your app version. Are the docs part of a release in any form? If not, then do you really want to create a new version number and build/release the app again?

[alexKeppler]

The arc42 document and the user manual have been reviewed by me and are approved for QG5.

[SebastianBezold]

Thx for reviewing @alexKeppler! @fabiodmota: what about the version? In my opinion, this is not necessary. Especially the minor version increase on the Chart without any changes made to the Chart.