I think it should be better documented how emoji are used for hyperlinks. I can not find any reference and solution to handle them. Here is my project where I tried hyperlinking with :desert_island: and also with the emoji itself. Both do not work.
For a header like ## :desert_island: Installation, the generated anchor ID is desert_island-installation — you can check this by previewing the change and hovering over the header to see its anchor. Emoji will be stripped out.
Most helpful comment
For a header like
## :desert_island: Installation, the generated anchor ID isdesert_island-installation— you can check this by previewing the change and hovering over the header to see its anchor. Emoji will be stripped out.