Use Crowdin for translations

Context and Problem Statement

The JabRef UI is offered in multiple languages. It should be easy for translators to translate the strings.

Considered Options

• Use Crowdin
• Use popeye
• Use Lingohub
• Keep current GitHub flow. See the Step-by-step guide.

Decision Outcome

Chosen option: "Use Crowdin", because Crowdin is easy to use, integrates in our GitHub workflow, and is free for OSS projects.