After months of speculation, Austin-based dating and professional networking app Bumble Inc. filed paperwork Friday for an initial public offering. It was not immediately clear how much the company hopes to raise from the IPO or what its valuation may be. In September, Bloomberg reported the company would seek a valuation of $6 billion to $8 billion. If validated, that valuation would be a significant jump from valuations market observers and investors placed on the company previously.