fix minor build errors when creating pdfs and html output

docker-based image validation

build all languages

added image validation task to gradle

update readme

updated

removed outdated files

updated generated templates, as we restructured the generator.

describe some requirements for the build process, as we are currently re-working that...

Fix zero-width space warning in ZH PDF build

updated directory structure

remove ZH files, as most have errors or are not complete

Add ZH distribution files

udpate readme with credentials for Chinese translation

Merge branch 'master' of https://github.com/arc42/arc42-template