docs: minimal reproduction documentation (#8107)

* first draft of minimal reproduction documentation

* prefer GitHub but other platforms are OK as well

* use friendlier tone

* Update minimal-reproductions.md

* after Prettier run

* Update docs/development/minimal-reproductions.md

Co-authored-by: HonkingGoose <34918129+HonkingGoose@users.noreply.github.com>

Co-authored-by: Rhys Arkins <rhys@arkins.net>

docs/development/minimal-reproductions.md

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+# About minimal reproductions
+
+You may be asked to provide a "minimal reproduction" repository to help the Renovate team debug bug reports.
+
+This document explains why we need a minimal reproduction, why using large repositories to debug is undesirable, and how you can create a good minimal reproduction.
+
+## What is a minimal reproduction?
+
+The basic idea of a minimal reproduction is to use the least amount of both code and config to trigger missing or wrong behavior.
+Having a minimal reproduction makes it easier for the developers to see where the bug is, and to verify that the new code fixes the bug.
+
+### Why not use the production repository to debug?
+
+You might think, why is a minimal reproduction even needed?
+I already have the reproduction on my production repository and it's public.
+Why not use that to debug?
+
+A production repository uses many dependencies, and can have a large list of custom rules in the Renovate configuration file.
+This makes it very hard to debug the repository, because there are many moving parts and debug statements could be triggered potentially hundreds of times.
+
+Also, it's quite common when configs are large that what people think a problem is simple but it's caused by two or more features interacting.
+Reducing the config to a minimum to reproduce the bug helps discover exactly which config elements are required to interact to trigger the bug.
+
+## Why we require a minimal reproduction
+
+Except for very simple bugs like typos, a debuggable reproduction repository is usually needed, and it makes most sense for the issue reporter to create it.
+We prefer that you use GitHub to host your reproduction, but if it requires GitLab or Bitbucket to be reproduced then creating a public repository on those instead is fine.
+
+### Making a reproduction repository is too much work for me
+
+Although we'd love to get down to zero reported bugs remaining, there's usually a queue and we need to prioritize.
+If a bug is not important enough for you to spend your time reproducing, that's a strong indicator to the Renovate team that it should be treated as a lower priority than those bugs which do have a reproduction repository.
+
+Therefore you are free to raise bug reports without a reproduction repository but be prepared for it to not be fixed until someone else with the same bug reproduces it, and for it to be closed unfixed if nobody else is able to do that.
+
+## How to create a good minimal reproduction
+
+A good minimal reproduction:
+
+- Uses the fewest amount of repository files and dependencies possible
+- Reduces the Renovate config to the minimum necessary
+
+Sometimes you may find it easiest to start with a fork and then remove files/config until the bug no longer reproduces, but other times it may be simplest to start with an empty repository with a couple of files you copy over manually from your main repository.