Add German language support to i18n.js (#1105)
Add German language support to i18n.js (#1105)

* Add German language support to i18n.js

* add `de` to `_locales` variable

* fix code format to fit JavaScript Standard Style

* fix variable typo in "de" dictionary

* add new containsInvalidProperties and containsInvalidItems translation keys to german i18n dictionary

Co-authored-by: s-a <a7f35a7fc3da9537756f8593ed4db84b5d72e644@gmail.com>
josdejong/jsoneditor,josdejong/jsoneditor