Allow choosing the grades from pre-defined lists #1

Letting users choose their grades entirely is tricky, since grades MUST be a non-ambiguously ordered set.

Let me say that again:

GRADES MUST BE A NON-AMBIGUOUSLY ORDERED LIST

Therefore, we're going to provide a bunch of pre-defined, hardcoded grades lists (gradations? — poets, help me) for the user to choose from.

Anyone is free to create a merge request to add new grades lists, and we can ensure this constraint stays enforced through reviews.

This issue is about suggesting new grades lists as unicode symbols, preferably using widely supported characters, given that we can use the font of our choosing.

So far, we have the following :

😫😒😐😌😀😍 (currently in use - note that in this issue another font is used)
🤮😒😐🙂😀🤩 (works on firefox but not chromium, on linux)
…

Add your suggestions here or in the comments !
Once we have a bunch of them we'll proceed to a MJ Poll 😉