Completed german translation for the plugin settings
Translated the description of the settings documentation
Used a nicer sentence for the room type description
Translated the Github-Links for the Roadmap
Implementing a new translating system, so we can more easily translate
settings strings. Indeed, these strings are difficult to embed in
JSON format.
We still use JSON files for standard strings, but in addition we have
dedicated YAML files to translate settings strings.
There is a new build-languages.js script that merge all translations in JSON files.
Other modifications:
* Eslint: ignoring documentation and build scripts.
* french settings translations.
