v3.31.0

• added: git machete git{hub,lab} update-{pr,mr}-descriptions subcommands
• added: git machete git{hub,lab} create-{pr,mr} --update-related-descriptions flags
• added: git machete git{hub,lab} restack-{pr,mr} --update-related-descriptions flags
• added: git machete git{hub,lab} retarget-{pr,mr} --update-related-descriptions flags
• added: machete.traverse.fetch.<remote> git config key to selectively exclude remotes from git machete traverse --fetch (contributed by @gjulianm)