Update CHANGELOG.md
Update CHANGELOG.md

(changes from PR of LWM added)
coders4help/volunteer_planner,klinger/volunteer_planner,christophmeissner/volunteer_planner,coders4help/volunteer_planner,pitpalme/volunteer_planner,klinger/volunteer_planner,christophmeissner/volunteer_planner,volunteer-planner/volunteer_planner,klinger/volunteer_planner,volunteer-planner/volunteer_planner,coders4help/volunteer_planner,klinger/volunteer_planner,pitpalme/volunteer_planner,volunteer-planner/volunteer_planner,coders4help/volunteer_planner,christophmeissner/volunteer_planner,pitpalme/volunteer_planner,volunteer-planner/volunteer_planner,christophmeissner/volunteer_planner,pitpalme/volunteer_planner