`SCConv` needs a full revision

[gbg141]

Two important concerns about SCConv simplicial model:

• [ ] Implementation of normalization: The original paper consider normalized incidence and adjacency matrices, but the proposed normalization procedure in the tutorial does not work. Currently, the model runs without any normalization.
• [ ] Improving readability: The notation of incidence and adjacency matrices is difficult to follow; this needs to be carefully revised for the model to be further used.