By Nivedita Balu and Greg Roumeliotis (Reuters) -Twitter Inc said on Tuesday it will offer Tesla boss and entrepreneur Elon Musk a seat on its board of directors, a position he plans to use to bring about significant improvements at the social media site. The move came after Musk disclosed in a regulatory filing on Monday that he had amassed a 9.2% stake in Twitter, making him its largest shareholder. Beyond the promise of big change, Tesla Inc’s CEO, who often chooses unconventional paths, has provided little detail. Even so, Musk will be involved in strategic decisions, including the directi…