Refrens, a Bengaluru-based startup that helps freelancers and small businesses with invoices and payment, announced it has raised funds from a group of angel investors including Paytm’s Vijay Shekhar Sharma and Shaadi.com founder Anupam Mittal. Other investors that took part in the funding round include early-stage fund Firstcheque, Gireesh Subramaniam of Freshworks, Sujayath Ali and…