Backlog section Curation: show sister impls

[Deleplace]

We currently show 3 samples of (Idiom X description + 1 single impl Y in current language L).

This can lead to confusion, as the contributor could be mislead into

• either "fixing" the impl according to their personal taste, while their personal taste already exists for X in L, as a distinct entry Y2
• or creating a new impl Y3 according to their personal taste, while their personal taste already exists for X in L, as a distinct entry Y2

To reduce the risk of confusion, consider displaying the full picture: all of the existing implementations Yn of X in L.