Adjusted the y-coordinate values for annotations with id 1, 2,
and 3 in annotations.json to reposition them on their respective
pages:
- Changed y for id 1 from 980.0 to 380.0.
- Changed y for id 2 from 980.0 to 680.0.
Added three new annotation objects to `annotations.json`.
Each annotation includes an `id`, `page`, `x`, and `y` property.
The annotations are for pages 1, 2, and 3, all with the same
coordinates (390.0, 980.0).
