So how exactly does one do this? The lillördag hashtag on Instagram offers a peek into how people celebrate the middle of the week: Platters of oysters, glasses of wine, whiskey, overflowing plates of pasta, pastries and prosecco, charcuterie spreads, and Nutella pancakes accompany lively conversation in cozy settings. Basically, celebrating lillördag doesn’t come with any preset rules. So long as you’ve disconnected…