LONDON — J.K. Rowling is publishing a fairy tale about truth and abuse of power free online so that children can read it during lockdown — and the first two chapters are available now.The remaining chapters will be released every weekday until July 10, Rowling said on Twitter, adding in capitals: “THIS IS NOT A HARRY POTTER SPIN-OFF.”Rowling got the idea for The Ickabog when she was writing Harry Potter and she intended it to be published after Harry Potter and the Deathly Hallows, the last of her seven-book Potter series.But the mostly handwritten manuscript of The Ickabog ended up in her attic and stayed there for a decade until a few weeks ago, stored in a box from high-end fashion retailer Net-A-Porter.