I use notion.so They support code snippets via code blocks. I use it for notes but also for much more. For example, my website (https://blog.kowalczyk.info/

I use notion.so They support code snippets via code blocks. I use it for notes but also for much more. For example, my website (https://blog.kowalczyk.info/ https://blog.kowalczyk.info/) is almost fully generated out of content stored in Notion via a custom program (https://github.com/kjk/blog https://github.com/kjk/blog) that uses my (unofficial, reverse-engineered) API library for Go (https://github.com/kjk/notionapi https://github.com/kjk/notionapi). Notion is very rich so it might be overwhelming at first but it's the last note-taking application I'll ever use.