Corrections and additions for the German language pack.

[wehro]

This includes additions for semicolon related messages and stylistical improvements.

[sangwinc]

Thanks @wehro for your continued interest. This is very helpful.

It's really important that language strings go through the Moodle translation process: https://lang.moodle.org/

Currently, only German language is distributed with STACK itself, because of the API. And @EJMFarrow just committed changed to dynamically download language packs as needed within the API, so this won't be necessary in the future. Indeed, if not we'll delete the German language file to avoid this kind of confusion!

You'll notice that I changed your pull request into "dev", because we just updated the German language pack here.

I submitted some of your suggestions through the Moodle translation process already, for review by the Moodle language pack maintainer.

[sangwinc]

@wehro thanks so much for this contribution. To keep the language strings up to date, and in once place, issue #1710 will now remove the German language packs as part of this plugin distribution. The API (the original reason for including them) now automatically gets the latest version of the language pack when you build the docker container. This is much better: we release a new version of STACK (with perhaps some new language strings). The translators can see the new strings, and add them, then you build the new docker for the API application. This pull request is, therefore, no longer needed. Please could you contribute your strings via https://lang.moodle.org/

Thanks!