Gifs is a great way to show game animations or bugs and there is great tools like ScreenToGif for example.
Could forum be able to display animated gif ?
It's already possible, just like with any other image. See below for an example:
I used the following Markdown code:
If posting from services such as Gfycat, it's a good idea to link to the original GIFV (which is of higher quality). It's also possible to make the GIF clickable with the following Markdown code:
Which results in:
I mean the forum "attach image/file" button doesn't support GIF.
I tried with this url, but it doesn't seem to work
Use the "raw" URL instead, which you can obtain by right-clicking the image and selecting Copy Image Location.