Use test-network.sh for the examples in Chutney's README

[teor]

Chutney's README is confusing, because we provide examples that assume you have already started a chutney network.

Instead, we should provide test-network.sh command lines.

[teor]

This is actually a really important documentation fix, if we want the anti-censorship team to be able to use chutney easily.

[teor]

Some of these tickets are part of the sponsor 31 CI improvements task, we will pick the specific tickets later, and assign them to people.

[gaba]

Sponsor closed. Remove from roadmap.

[teor]

Change tickets that are assigned to nobody to "new".