Update dom helper documentation
Update dom helper documentation

tildeio/htmlbars,GavinJoyce/htmlbars,glimmerjs/glimmer-vm,step2yeung/htmlbars,chadhietala/glimmer,tildeio/glimmer,kublaj/htmlbars,step2yeung/htmlbars,mixonic/htmlbars,davidgoli/htmlbars,duggiefresh/htmlbars,chancancode/htmlbars,code0100fun/htmlbars,tildeio/glimmer,Kuzirashi/htmlbars,chadhietala/glimmer,lbdm44/glimmer-vm,glimmerjs/glimmer-vm,rodrigo-morais/htmlbars,lbdm44/glimmer-vm,tildeio/htmlbars,duggiefresh/htmlbars,mixonic/htmlbars,cgvarela/htmlbars,jayphelps/htmlbars,jayphelps/htmlbars,salzhrani/htmlbars,xcskier56/htmlbars,greyhwndz/htmlbars,GavinJoyce/htmlbars,lbdm44/glimmer-vm,vinngn1/htmlbars,chadhietala/glimmer,stefanpenner/htmlbars,code0100fun/htmlbars,chancancode/htmlbars,xcskier56/htmlbars,stefanpenner/htmlbars,chadhietala/glimmer,kublaj/htmlbars,tildeio/glimmer,greyhwndz/htmlbars,cgvarela/htmlbars,simudream/htmlbars,simudream/htmlbars,SerkanSipahi/htmlbars,Kuzirashi/htmlbars,davidgoli/htmlbars,vinngn1/htmlbars,SerkanSipahi/htmlbars,salzhrani/htmlbars,glimmerjs/glimmer-vm,rodrigo-morais/htmlbars