v0.12.98: @newsroom.writer: smaller screenshots

Screenshots were shown at the full width of the article, far bigger than they need to be. In I just want to buy the article, HBR's sign-up dialog now shows at 42% of the column, and HBR's plans, the newsroom's card and the reading account at 62%. In Our first PR in Ruflo, the six GitHub screenshots show at 78%, as their text is smaller. On a phone they widen again, and every screenshot still opens at full size. The figures drawn for the articles keep the full width. No text changed.