404 links in the welcome page

[sebherbert]

Hi,

I think 2 links on the main page: https://csbdeep.bioimagecomputing.com/ are dead.

Real-world scenarios: https://frauzufall.github.io/csbdeep-testsite/scenarios
and
methods and tools: https://frauzufall.github.io/csbdeep-testsite/tools

Otherwise thanks for the super nice website!

Cheers,

Sebastien