Indra Nooyi stepped down as the CEO of PepsiCo. As she did, the outgoing exec reflected on career lessons learned in a special ‘goodbye’ letter to employees. In this LinkedIn post, she encouraged her staffers to set goals, listen openly to feedback and pursue lifelong education. Most crucially, she told them: “Think hard about time.” Nooyi was PepsiCo’s first female chief executive and boosted revenue…