Added note about preloading issues to Readme
Added note about preloading issues to Readme

Draper's initialization may cause issues with application configuration
being ignored (see #202). Note the problem and possible workaround in
the docs.

outstand/draper,drapergem/draper,baberthal/draper,drapergem/draper,sideci-sample/sideci-sample-draper,yui-knk/draper,jianyuan/draper,krainboltgreene/draper,liwangbest/draper,chuck-john/draper,drapergem/draper,mallikarjunayaddala/draper,estum/draper,SpencerCDixon/draper,Bastes/draper,totzyuta/draper,mallikarjunayaddala/draper,liwangbest/draper,outstand/draper,turingschool/draper,yui-knk/draper,estum/draper,donaldpiret/draper,jianyuan/draper,Bastes/draper,SpencerCDixon/draper,baberthal/draper,totzyuta/draper,turingschool/draper,chuck-john/draper