text: Title: Add support for new kinds of nerves: n-simplices and min-intersection.
  Body: Now that @michiexile abstracted a nerve class, we can include support for other nerves. Most obvious are a min-intersection nerve and an n-simplices nerve. Though I believe we will also need a custom nerve for multi-mapper and we could experiment with a multi-nerve.
  
  - [x] min-intersection
  - [ ] n-simplices
  
  
  ## min-intersection
  
  It would be nice to set a minimum number of points each cluster has to intersect on to be considered connected.
  
  ```
  edges = nerve({"a": [1,2,3], "b": [2,3,4], "c": [4,5,6]}, min_intersection=2)
  -> ["a", "b"] in edges and ["b", "c"] not in edges
  ```
  
  ## n-simplices 
  
  It would be nice to have a general n-simplex nerve that constructs simplices of order n or less.
  
  Before building this, is there an established format for simplexes? Are there any libraries that we could use?
  Most promising simplicial complex libraries found in the wild:
  - [pycomplex](https://github.com/EelcoHoogendoorn/pycomplex)
  - [simplicial](https://github.com/simoninireland/simplicial)
  
  I'd prefer not to reinvent the wheel but I think a strong python simplicial complex library could be useful to the community.
  