Improve Custom Event types

Sounds like there's a potentially better way for handling CustomEvent types: https://stackoverflow.com/a/68783088

Is there room for improvement where we're using custom events for callbacks?

CldVideoPlayer: https://github.com/colbyfayock/astro-cloudinary/pull/2/files#diff-499428a7954282f9e77a1d76faecccf1a33effd72d8538bef205c3f048ff862fR133-R141

This should also help improve and clear up the types in the demos and examples, such as DemoVideoPlayerEvents.astro from the docs

Update example in Basic Usage to include new syntax