notmuch: add changelog to meta

Changed files
+1
pkgs
applications
networking
mailreaders
notmuch
+1
pkgs/applications/networking/mailreaders/notmuch/default.nix
···
meta = with lib; {
description = "Mail indexer";
homepage = "https://notmuchmail.org/";
+
changelog = "https://git.notmuchmail.org/git?p=notmuch;a=blob_plain;f=NEWS;hb=${version}";
license = licenses.gpl3Plus;
maintainers = with maintainers; [ flokli puckipedia ];
platforms = platforms.unix;