Fix Code-Contributions Repository link formatting in German README

[Awakenlegend]

his PR fixes the formatting of the Code-Contributions Repository link in the 'Wie geht es weiter?' section of the German translation of the README.
Removed the space in the Markdown link.
Ensured there is no Slack link in this section.
Issue reference:
Addresses #94132

[Roshanjossey]

Hello, congratulations! You've successfully submitted a pull request. 🎉

If you liked the tutorial, please star this repo by clicking the star button on the top right of this page.

Next steps

• Continue contributing: If you're looking for projects to contribute to, checkout our webapp.

• If you want more practice checkout code contributions.

• Share on social media: You can share this content to help more people.

  • Post on Bluesky.
  • share.
  • share.
  • post.
  • publish.
  • post.
  • tweet.

We'd love to hear your thoughts about this project. Let us know how we can improve by commenting or opening an issue here.