By Sarah McBride SAN FRANCISCO (Reuters) – Forget striving for a well-rounded resume. According to a new book from Peter Thiel, the investor and PayPal co-founder, well-roundedness amounts to “many-sided mediocrity.” Instead, his “Zero to One” urges entrepreneurs to “focus relentlessly on one thing you’re good at doing.” And yet this very readable and provocative book by Thiel, a Stanford graduate with a degree in philosophy, draws on sources from Shakespeare to Roman history to Lady Gaga and amounts to a testament to the value of generalization. …