docs: fix duplicate urwid-tutorial reference
docs: fix duplicate urwid-tutorial reference

harlowja/urwid,tonycpsu/urwid,douglas-larocca/urwid,wardi/urwid,harlowja/urwid,inducer/urwid,tonycpsu/urwid,tonycpsu/urwid,urwid/urwid,foreni-packages/urwid,drestebon/urwid,wardi/urwid,douglas-larocca/urwid,inducer/urwid,ivanov/urwid,douglas-larocca/urwid,harlowja/urwid,foreni-packages/urwid,hkoof/urwid,rndusr/urwid,ivanov/urwid,foreni-packages/urwid,rndusr/urwid,urwid/urwid,rndusr/urwid,hkoof/urwid,urwid/urwid,wardi/urwid,ivanov/urwid,hkoof/urwid,drestebon/urwid,inducer/urwid,drestebon/urwid