as a user, i can click on a task and expand all of its details in a modal

[henrylin03]

lofi wireframe:

may need to do #15 when dealing with the checkbox here. the handler should be the same as user clicking the checkbox outside of the modal just in <main> (when tasks are previewed) (see below)

[henrylin03]

#18 has completed all but one properties of a task from localStorage. what is missing is the "completed" status - if the task is completed, then the checkbox should already be ticked. there may need to be more thoughts on how to design a completed task (eg whether colour of the modal background should be the same as a completed <div> etc). leaving this issue open until #15 and #17

[henrylin03]

as of #24, if a task has completed status, the checkbox is already ticked

design of the task details modal for a completed task can be explored in the future - added as a potential task in #4 for future