The coronavirus has shuttered many small businesses that do our work and supply our things. So, millions of people who are trying to stay home are being driven by necessity — or boredom — to relearn some old household skills. That means things like mending clothes and cutting hair and baking bread and fixing a dripping faucet. In difficult times it can be an emotional lift to find you’re more capable around the house than you thought. Demand is up for how-to videos on YouTube and for home-repair and lawn tools. Not to mention baking supplies.