Automate updating generated content in README

[slarse]

Such as the list of contributors and the list of releases.

[algomaster99]

Isn't it a better idea to link the insights/contributors list? The list is available under two conditions - either the repository is public or the organization needs to upgrade to GitHub team, and we qualify the first the condition.

[slarse]

That was my thought too, but as @monperrus then pointed out, we have contributors that predate GitHub and thus aren't shown there.

[monperrus]

we can have a CI job which detects if the list is outdated and automatically create a PR accordingly based on the output of chore/generate-contributor-list.py.