[BUGFIX] Welcome screen now points to correct docs
[BUGFIX] Welcome screen now points to correct docs

This fixes the links to the FLOW3 documentation appearing at
the Welcome screen.

Change-Id: Id677c44c3b203fa3598e125aacd55fb941bc2da0
Resolves: #28883

kdambekalns/flow-welcome,neos/flow-welcome,kdambekalns/flow-welcome,neos/flow-welcome