Add JSON example for annotations in file upload form

currently : "Attach these annotations with the uploaded files:" followed by text field

make it more clear as to what we expect the user to enter in this field

changed the description

assigned to @boucherg

unassigned @boucherg

added Doing label

assigned to @JonathanSeguin

created merge request !72 (merged) to address this issue

mentioned in merge request !72 (merged)

closed with merge request !72 (merged)

mentioned in commit 4b7f53f6