I don't actually know if this isn't allowed already, but I'm assuming not as I've never seen anyone post any webm videos on the site. Now I can appreciate why you wouldn't want people posting full on porn videos, but consider the below as a counterpoint: I've been reading a particular story in recent weeks that makes liberal use of gif images to spice up the story, and I quite like it, but I have noticed that they often take quite a while to load. When pondering why that was, I saved one gif from this story to look at it and realized it was pretty large. To give some numbers for context; the gif was 12.3 mb in size, and when converted to a webm (video) format, it was reduced to 1.17 mb. This is a more than 10x reduction in size, with no noticeable quality loss (in fact it looked slightly better to me). I'm aware CHYOA doesn't actually host the images or videos on site anyway, so I guess they don't particularly care about the speed, but if users are given the capability to link to webm videos instead of just gif animations, they will load much faster for the user - like 10x faster. They can also support sound, I suppose, which may or may not be a good thing, but that can be set to mute by default regardless. Here's a link for more info on the point. https://web.dev/replace-gifs-with-videos/
The ability to link to images is a standard feature of the Markdown syntax. CHYOA uses this syntax to store content. Before user content is sent to a user's browser, a third-party plugin translates the Markdown syntax into HTML. That plugin will create an HTML img tag for the respective Markdown syntax. Browsers usually only support some image formats but no videos. Thus, video formats don't work with Markdown. So it's not forbidden but just doesn't work. That would definitely be a concern.
So I guess the answer is that things don't work that way, and that nothing is going to change in that regard. Forgive me for thinking so but it seems to rather be the answer to all suggestions for this site. I made some criticisms of the busted notification system two years ago now, and the only reply I got was someone linking me like four other people who made a similar suggestion; and two years later it is still unchanged. And near as I can tell the change I suggested then would be extremely trivial to implement. As for this, if a standard markdown system doesn't allow for higher performance file formats, maybe it's time to consider changing it. I know for a fact there are many, many editors online that allow for linking to video files. As to the point about sound, it's a nonissue if they want to disable it. The link I posted has the code for how to make a webm video play identically to a gif animation, non-expandable, autoplay, looping and muted.
I answered in regard to your assumption that it would be forbidden to post videos on the site. (Though then it wouldn't make much sense to allow .gif anyway.) This site has a forum Suggestions that is a subforum of Site Feedback. There, you can post suggestions and other users can vote for the suggestion by liking the initial post of that thread. Suggestions with more likes are more likely considered to be implemented. The reasons I link to related suggestions are to keep track of similar suggestions and to point users who might like the given suggestions alternatives without having to search for them. For me, the last three years were pretty busy, so I had basically no time to work on improvements for the site. Though my schedule will change a lot in a few months and I'm looking forward to working on the next version of CHYOA and implementing many of the suggestions.
I've encountered enough code bases to know that few features are trivial, and worse still, without at least a surface level familiarity with the code base in question, it's virtually impossible to tell the few that are from the many that aren't.
