docs: added docstring for gzip_reader
docs: added docstring for gzip_reader

pavlobaron/disco_playground,seabirdzh/disco,ErikDubbelboer/disco,oldmantaiter/disco,beni55/disco,discoproject/disco,scrapinghub/disco,scrapinghub/disco,oldmantaiter/disco,seabirdzh/disco,simudream/disco,discoproject/disco,scrapinghub/disco,mozilla/disco,simudream/disco,pavlobaron/disco_playground,beni55/disco,ErikDubbelboer/disco,pombredanne/disco,scrapinghub/disco,ktkt2009/disco,oldmantaiter/disco,pavlobaron/disco_playground,ErikDubbelboer/disco,ktkt2009/disco,mwilliams3/disco,seabirdzh/disco,mwilliams3/disco,oldmantaiter/disco,mwilliams3/disco,pombredanne/disco,mwilliams3/disco,mwilliams3/disco,pooya/disco,mozilla/disco,discoproject/disco,pombredanne/disco,pavlobaron/disco_playground,ktkt2009/disco,discoproject/disco,pombredanne/disco,oldmantaiter/disco,discoproject/disco,simudream/disco,simudream/disco,seabirdzh/disco,beni55/disco,beni55/disco,pombredanne/disco,ktkt2009/disco,seabirdzh/disco,ErikDubbelboer/disco,pooya/disco,ktkt2009/disco,ErikDubbelboer/disco,mozilla/disco,pooya/disco,simudream/disco,beni55/disco,mozilla/disco,pooya/disco