By Svea Herbst-Bayliss and Greg Roumeliotis (Reuters) -Twitter Inc kicked off deal negotiations with Elon Musk on Sunday after he wooed many of the social media company’s shareholders with financing details on his $43 billion acquisition offer, people familiar with the matter said. The company’s decision to engage with Musk, taken earlier on Sunday, does not mean that it will accept his $54.20 per share bid, the sources said. It signifies, however, that Twitter is now exploring whether a sale of the company to Musk is possible on attractive terms, the sources added. Musk, chief executive of el…