docs: Erstes vollständiges Dokumentations-Setup (Anwender-Wiki, Entwickler-Wiki, README.md, CHANGELOG.md)

- Docusaurus für Anwenderdokumentation (/docs)
- Zweiter Docusaurus-Bereich für Entwickler-Wiki vorbereitet (/docs/entwickler)
- README.md als Einstieg für Entwickler
- CHANGELOG.md zur Nachverfolgung von Änderungen
→ Dokumentation und Projektstruktur jetzt vollständig nachvollziehbar versioniert.

docusaurus/README.md

@@ -0,0 +1,41 @@
+# Website
+
+This website is built using [Docusaurus](https://docusaurus.io/), a modern static website generator.
+
+### Installation
+
+```
+$ yarn
+```
+
+### Local Development
+
+```
+$ yarn start
+```
+
+This command starts a local development server and opens up a browser window. Most changes are reflected live without having to restart the server.
+
+### Build
+
+```
+$ yarn build
+```
+
+This command generates static content into the `build` directory and can be served using any static contents hosting service.
+
+### Deployment
+
+Using SSH:
+
+```
+$ USE_SSH=true yarn deploy
+```
+
+Not using SSH:
+
+```
+$ GIT_USER=<Your GitHub username> yarn deploy
+```
+
+If you are using GitHub pages for hosting, this command is a convenient way to build the website and push to the `gh-pages` branch.