Added documentation for before/after-header-row hooks
Added documentation for before/after-header-row hooks

fguillot/kanboard,BlueTeck/kanboard,Busfreak/kanboard,patoi/kanboard,libin/kanboard,oliviermaridat/kanboard,oliviermaridat/kanboard,stinnux/kanboard,kanboard/kanboard,fguillot/kanboard,stinnux/kanboard,Busfreak/kanboard,libin/kanboard,BlueTeck/kanboard,renothing/kanboard,Busfreak/kanboard,filhocf/kanboard,stinnux/kanboard,filhocf/kanboard,oliviermaridat/kanboard,thylo/kanboard,fguillot/kanboard,renothing/kanboard,patoi/kanboard,filhocf/kanboard,patoi/kanboard,thylo/kanboard,kanboard/kanboard,thylo/kanboard,BlueTeck/kanboard,renothing/kanboard,kanboard/kanboard