Document use of both upstream Git and tarballs (and drop Git-only note).
Document use of both upstream Git and tarballs (and drop Git-only note).

tchx84/debian-pkg-sugar-artwork,tchx84/debian-pkg-sugar-toolkit,tchx84/debian-pkg-sugar-toolkit,tchx84/debian-pkg-sugar-base,tchx84/debian-pkg-sugar-artwork,tchx84/debian-pkg-sugar-base,tchx84/debian-pkg-sugar-base,tchx84/debian-pkg-sugar-artwork,tchx84/debian-pkg-sugar-toolkit