feat: animate hide

[BeksOmega]

Fixes: #57

This change introduces an animation to the hide() method, making the annotation disappear with a reverse animation of the show() method.

Previously, hide() would immediately remove the annotation's SVG elements from the DOM. This change modifies the hide() method to:

• Play the show() animation in reverse.
• Use requestAnimationFrame to ensure the animation restart is smooth.
• Use setTimeout to remove the SVG elements only after the animation has completed. This prevents race conditions when show() is called again while a hide() animation is in progress.

Tested

Added a demo page so you can pull this down and try it as well!

Contributing

Not sure what your contribution guidelines are, but just FYI the first pass at this was done with AI. The Jules product / Google doesn't claim any copyright over code generated by Jules though.

For my ref

Task ID: https://jules.google.com/task/18159235495996926247

[Nkay]

I just thought about adding that. Thank you :)