Documentation quality can make or break an open source project. Don't believe me? Ever used poor documentation? How did it make you feel about your continued use of the software?
Just as Postgres's high code quality doesn't happen by accident, neither does its documentation quality. Our community is regularly updating and improving our documentation — since 1998, our documentation has averaged 1.3 commits per day. Don't believe me? See for yourself — that's 6913 documentation improvements over 14 years.