Dark and light color schemes are not yet widely supported by browsers. Nonetheless when coded correctly it will bring no harm to your website and will actually allow users to enjoy custom color schemes.
Async generators allow using a series of async events as if they were iterable. It’s probably the first significant step to take to learn reactive programming.
First of all: why singleton? Isn’t it widely considered an antipattern?
What has been will be again, what has been done will be done again; there is nothing new under the sun.