Big boardroom news has just shaken up Pinterest (PINS), and if you follow the company’s stock, this is one of those moments that could be worth a second look. Jeremy Levine, a long-time independent director, has retired from the board, and in his place steps Emily Reuter, Instacart’s chief financial officer. The shift did not stem from any disagreement. By all accounts, it is about new energy and expertise. With Reuter’s background at Instacart and Uber, Pinterest is signaling a push to…