docs for #130
docs for #130

wolfgangwalther/jsPsych,jspsych/jsPsych,wolfgangwalther/jsPsych,vergenzt/jsPsych,shamrt/jsPsych,msrresearch/jsPsych,jodeleeuw/jsPsych,Scienthusiast/jsPsych,shamrt/jsPsych,andyh616/jsPsych,vergenzt/jsPsych,erikasf/jsPsych,jspsych/jsPsych,erikasf/jsPsych,jspsych/jsPsych,adrianoesch/jsPsych,jspsych/jsPsych,adrianoesch/jsPsych,Scienthusiast/jsPsych,andyh616/jsPsych