Various fixes: eslint, broken animation, contributors, and more challenges links

[commjoen]

What kind of changes does this PR include?

• Fixes or refactors
• A new challenge
• Additional documentation
• Something else

Description

This PR undoes the animation introduced in the previous PR, fixes eslint rules, adds missing contributors on home and readme, and adds texts that show that there are more challenges in case you hit a "disabled" challenge.

Relations

References

Checklist:

• All the contributions made are solely the work of me and my co-authors
• I tested the changes in this PR (if applicable)
• I added unit tests to ensure my change works (when change in Java or on front-end code)
• I added UI tests to ensure my UI changes work (when change in the overall UI, not needed if just adding a challenge)
• The PR passes pre-commit hooks and automated tests