Update KMouth docbook to kf5

Summary:
remove entities kmouth, kappname, package, either defined in kdoctools or unused in kf5
bump date + releaseinfo
update + proofread
remove jovie - bye you served us well ;-)
comment for now appendix tts - completely outdated :-( I need input/ifos from whiting gladhorn
remove appendix installation
remove chapter faq

I tested kmouth in neon devedition unstable and got it to work :-(

BIG QUESTION:
in neon-devedition-unstable i have a male speaker in english
how do I change speaker and language?

Test Plan: checkXML5 index.docbook

Reviewers: #documentation, whiting, gladhorn

Reviewed By: whiting

Subscribers: gladhorn, whiting, #documentation

Differential Revision: https://phabricator.kde.org/D9667