PR template references non-existent CONTRIBUTING.md

### What You Are Seeing?

The docs PR template insists that you read CONTRIBUTING.md in very strong language, but there is no such file in the docs repo.

https://github.com/chocolatey/docs/blob/8c242f4a58f7d19ab6fe11714582ced36e5db732/.github/PULL_REQUEST_TEMPLATE.md?plain=1#L4

### What is Expected?

The docs PR template should link to the appropriate file. If it's in another repo, the link should be updated. If there's no longer a relevant CONTRIBUTING.md file for the docs repo, the template should be updated to provide up-to-date guidance.

### How Did You Get This To Happen? (Steps to Reproduce)

1. Try opening a docs PR.
2. Read the large comment at the top of the PR template.

Start with .github/PULL_REQUEST_TEMPLATE.md at the referenced line and inspect the docs repository for the current contributor guidance. Confirm whether a suitable CONTRIBUTING.md exists in another repository or whether the template needs updated guidance; done means the template no longer points to a nonexistent file.

Written by the indexing model from the issue text.