Move "sandbox" code to its own repository

[leogr]

Motivation

As this repository is becoming more and more critical for decision-making and documenting the whole project, I think it would be a good idea not to mix the documentation with the experimental code. I find it more straightforward and consistent that such source code would live in its repository.

Feature

1. create the falcosecurity/contrib repository
2. Move the following directories (preserving the git history) to the new repository:
   • https://github.com/falcosecurity/evolution/tree/master/examples
   • https://github.com/falcosecurity/evolution/tree/master/integrations
   • https://github.com/falcosecurity/evolution/tree/master/usage-metrics/distribution-logs (or to test-infra?)
3. Update the README.md accordingly

Alternatives

We might altogether remove the sandbox level. But I'd like that since such experimental code is still important to test-drive ideas or to provide examples.

Additional context

contrib is the former name of evolution and has also been suggested by @maxgio92, so I really believe it's the perfect name :smile_cat:

[maxgio92]

As discussed we're on the same page and I like the idea to have a contrib-dedicated repository.

[jasondellaluce]

I like this idea!

[leogr]

I'm working on this

/assign