chore: Update README

[susnux]

1. Fix broken screenshot
2. Add basic information for usage (old example was using the wrong event)
3. Adjust REUSE information

before	after

[susnux]

exclamation mark is not needed since this doesn't get compiled to an asset :)

I will fix this, but I personally prefer the "license" notation /*! because the /** notation is considered documentation.
Here it does not make a difference, but if you generate code documentation the SPDX-... would be considered the documentation for the class 😅

[come-nc]

exclamation mark is not needed since this doesn't get compiled to an asset :)

I will fix this, but I personally prefer the "license" notation /*! because the /** notation is considered documentation. Here it does not make a difference, but if you generate code documentation the SPDX-... would be considered the documentation for the class 😅

What about /*?