docs: credit maintainers and contributors

[HonkingGoose]

Changes:

• Credit:
  • Maintainers
  • Frequent contributors for smaller parts
  • Helpful contributions, even one-offs
• Bump amount of contributors to Renovate to 600

Context:

Closes renovatebot/renovate#11187

[HonkingGoose]

I found a way to find out some contributions from the people in the list.

For example, you can use https://github.com/renovatebot/renovate/search?q=author%3AHonkingGoose+sort%3Aauthor-date&type=commits to show my commits on the main Renovate repository.

And you can further filter by using keywords like feat, again using my username as example:

https://github.com/renovatebot/renovate/search?q=author%3AHonkingGoose+sort%3Aauthor-date+feat&type=commits

We can also find review work by an user on merged PRs, like this: https://github.com/renovatebot/renovate/search?o=desc&q=reviewed-by%3AHonkingGoose+is%3Amerged&s=created&type=issues

[rarkins]

I forgot that this file was in this repo. Would it make sense to move it into the main repo now?

[HonkingGoose]

@rarkins want me to move the file into the docs/usage directory on our main Renovate repo then?

[rarkins]

@HonkingGoose yes please