Doc: add troubleshooting information to tutorial

Add links to information about adding Qt versions and
compilers and configuring kits to the "Building and
Running an Example" tutorial.

Change-Id: I57892ae6ca58ccccfda6512b2b3b9f5bce17b4da
Reviewed-by: Sze Howe Koh <szehowe.koh@gmail.com>
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>