Wash and dry produce. Halve, peel, and thinly slice shallot. In a large, microwave-safe bowl, combine shallot, vinegar, 1 tsp sugar, and ½ tsp salt. Cover with plastic wrap and microwave for 60 seconds. Set aside, stirring occasionally. Meanwhile, drain mango. Mince cilantro. Open package and drain any liquid from shrimp. Heat a drizzle of oil in a large pan over high heat. Add shrimp; season with salt and pepper. Cook, stirring occasionally, until warmed through, 30 to 60 seconds. Transfer to a cutting board and let cool slightly. Roughly chop shrimp into bite-size pieces. Stir shrimp and mango into bowl with pickled shallot. Let sit for about 1 minute, then drain. Stir in cilantro. Transfer to a serving bowl and serve with tortilla chips on the side.