Added computer vision tasks
Looks great, thanks ! If the 3d ones are really rare we can remove them for now.

And I can see that `object-detection` and `semantic-segmentation` are both task categories (top-level) and task ids (bottom-level). Maybe there's a way to group them and have less granularity for the task categories. For example `speech-processing` is a high level task category. What do you think ?

We can still update the list of tasks later if needed when we have more vision datasets
 @lhoestq  @osanseviero I used the categories (there were main ones and subcategories) in the paperswithcode, I got rid of some of them that could be too granular. I can put it there if you'd like (I'll wait for your reply before committing it again) We can ignore the ones that are too granular IMO. What we did for audio tasks is to have them all under "audio-processing". Maybe we can do the same here for now until we have more comprehensive tasks/applications ?
Added various image processing/computer vision tasks.