By Abhirup Roy and Phuong Nguyen LAS VEGAS (Reuters) -Vietnamese electric vehicle maker VinFast aims to increase its free float, or shares available to the public for trading, to 10% to 20% by the end of this year from roughly 2% currently, the company’s chairperson said on Tuesday. “This year we plan as the markets recover and as we show more achievements of progress, we will do follow-on transactions … increasing the free float, bringing in many more investors, including long-only investors,” Le Thi Thu Thuy, the former CEO and current VinFast chairperson, told Reuters on the sidelines of …