Represents the user clicking somewhere in the text, moving the cursor to the position.
Optionally the selection the mouse made when clicking.
Normally there are two ways a someone can create selections with a mouse: the first is clicking and dragging the mouse, the second is double clicking on a word.
The idea is that the `selection` covers the second use-case: double clicking on a word. In the animation you will see the selection happen instantly.
For first use-case: mouse click selection, it is better to use a keyboard event using `⇧←` or `⇧→`. This way you animate the selection growing.