Layout the timeline to create an experiment

Front-end

This task has to do with the creation of a layout option to add new trials to an experiment. In this context, you first need to read on the Timeline of jsPsych.

• Layout a Gantt-chart object
• Map the layout on the Gantt-chart to the timeline from jsPsych.

This issue has to also map-out how to match that with the CSV option mentioned in #4.