Update all readmes

[merelcht]

Motivation and Context

Closes https://github.com/kedro-org/kedro/issues/3111

I made all spaceflight starter README.md files consistent. And updated any outdated info.

Checklist

• [ ] Opened this PR as a 'Draft Pull Request' if it is work-in-progress
• [ ] Assigned myself to the PR
• [ ] Added tests to cover my changes

[stichbury]

Thanks for the changes @merelcht -- all look good to me. I committed them.