doc: Clarified units in Element.cumulativeOffset and added example.
doc: Clarified units in Element.cumulativeOffset and added example.

Jiasm/prototype,ridixcr/prototype,sdumitriu/prototype,erpframework/prototype,loduis/prototype,ShefronYudy/prototype,Jiasm/prototype,fashionsun/prototype,Jiasm/prototype,erpframework/prototype,Gargaj/prototype,sstephenson/prototype,Gargaj/prototype,fashionsun/prototype,Gargaj/prototype,292388900/prototype,ldf7801528/prototype,ShefronYudy/prototype,loduis/prototype,ldf7801528/prototype,ridixcr/prototype,ldf7801528/prototype,292388900/prototype,ShefronYudy/prototype,ridixcr/prototype,loduis/prototype,lamsieuquay/prototype,sdumitriu/prototype,lamsieuquay/prototype,baiyanghese/prototype,leafo/prototype,leafo/prototype,sstephenson/prototype,sdumitriu/prototype,292388900/prototype,sstephenson/prototype,erpframework/prototype,baiyanghese/prototype,lamsieuquay/prototype,fashionsun/prototype