From DCist contributor Rebecca Walters: As Washington fans got their first official taste of the area’s “Return of the King,” little did they think one of their stars would be sidelined before the season even got off the ground. The 20-17 Redskins pre-season win over the Broncos was bittersweet as veteran Jon Jansen went down with a ruptured Achilles tendon. What this means for Washington’s 2004 hopes and dreams? Well, DCist can still see a…