The rabbit hole may have been in a black box, but the adventures were just as deep in Mill Mountain Theatre Conservatory’s “Alice,” which opened its run of free shows Saturday on Waldron Stage. The family-friendly adaptation by Anna Kimmell is an abridged — weighing in at about 45 minutes — and contemporary interpretation of Lewis Carroll’s “Alice’s Adventures in Wonderland” that celebrates the classic novel’s 150th anniversary. “Alice” opens with the character Alice, played