Update docs/topics/downloader-middleware.rst
Update docs/topics/downloader-middleware.rst

Co-Authored-By: Adrián Chaves <a1b909ec1cc11cce40c28d3640eab600e582f833@chaves.io>
scrapy/scrapy,pawelmhm/scrapy,scrapy/scrapy,pawelmhm/scrapy,elacuesta/scrapy,starrify/scrapy,elacuesta/scrapy,starrify/scrapy,pablohoffman/scrapy,eLRuLL/scrapy,starrify/scrapy,scrapy/scrapy,dangra/scrapy,dangra/scrapy,pablohoffman/scrapy,elacuesta/scrapy,eLRuLL/scrapy,eLRuLL/scrapy,pablohoffman/scrapy,pawelmhm/scrapy,dangra/scrapy