The first popular nostr clients are mostly social clients, including Damus, nostrgram, Iris, Amethyst, snort.social, etc.
These "notes" don't allow modifications nor markdown.
The protocol has defined recently a new use case that allows to use nostr to publish and distribute longer form content, as blog posts.
Some nostr clients/webs have started to be developed to support this use case.
i.e. https://habla.news
#[6] is working on it, if you are interested in following its development.
These "long form content" notes allow modifications and markdown.
