NY Post may be compensated and/or receive an affiliate commission if you buy through our links. Brooklyn’s small businesses aren’t letting the Grinch — or the ongoing supply chain shortages — ruin Christmas. Savvy store owners have come up with creative and crafty ways to keep their shelves full and customers happy. “We started seriously stocking up in late May and now have a massive amount of inventory,” Mary Meyer, co-founder of Bushwick store Friends NYC, told The Post of the retailer’s holiday season prep. So — after you read this story, of course — close your browser window, get out of your apartment, and get back to shopping in real life!…