Channel 5’s Liz Brunner is leaving her post after 20 years to start her own company. Brunner Communications will be a media training and consulting firm that caters to everyone from authors to executives. She’ll also train anchors and reporters. “My husband and I are empty-nesters so this is the perfect time to be able to create my own schedule,” Brunner told us on Wednesday. Brunner’s last day on air will be Oct. 17. There are no plans for a farewell party yet, Brunner told us, but we’re sure her WCVB friends will mark the occasion.