Improve board urls
The main motivation is that the current URLs can be confusing, and are quite ugly. Notably, the n-th board is not reachable as /board/n, but typically as /board/m for some n != m
The main motivation is that the current URLs can be confusing, and are quite ugly. Notably, the n-th board is not reachable as /board/n, but typically as /board/m for some n != m