Computes unique edges for a list of faces

`edges(faces | geometry)`

Parameters:

`faces`

- list of face indices e.g. `[[0,1,2,3], [3,2,5,4],...]`

`geometry`

- simplicial complex geometry `{ positions: [], cells: [] }`

Returns:

If `faces`

is supplied a list of edges will be returned e.g. `[[0,1], [1,2],...]`

If `geometry`

is supplied a new geometry with cloned positions and edge cells will be returned.

```
var computeEdges = require('geom-edges');
var faces = [[0,1,2,3], [3,2,5,4],...];
var edges = computeEdges(faces); //[[0,1], [1,2], ...]
```

MIT, see LICENSE.md for details.