It's non obvious for users of the site to figure out how to contribute things by reporting bugs or creating PRs to fix them. Let's add a link to the github page in the header to make that easier for them.

See for example this email, that was first on pgsql-bugshttps://www.postgresql.org/message-id/78c6b9661e1f88988b9b4fcd29b42751@postgrespro.ru