The restaurant and concert venue Beat Hôtel is now open at 13 Brattle St., bringing live music, colorful décor, and a taste of “la vie bohème” to Harvard Square. Led by the same team that operates The Beehive in Boston’s South End, the Beat Hôtel draws inspiration from a rundown hotel in Paris that housed numerous writers and artists of the so-called Beat Generation during the 1950s and ’60s, according to Jack Bardy, Beat Hôtel’s operating partner.