Drop universal framing and reduce feature walkthrough. README now names
the actual class and school, points at the live deployment, and keeps
only the bits needed to clone/run locally.
README in German with universal framing (class, study group, cohort)
rather than INFO1-specific wording. MIT license. Update package.json
with description, keywords, repository URL, proper license field,
start script. Add .env.example documenting required environment
variables.
Simon