Satsuma Indexing

[aguzmant103]

Satsuma is a subgraph indexing and querying platform.

Create a Subgraph of Semaphore contracts so that the data can easily be queried with APIs https://docs.satsuma.xyz/getting-started

[cedoor]

@semaphore-protocol/core I'm not sure if we should support this as well. Supporting TheGraph is already time-consuming. Could be a side-project separate from Semaphore tho. Wdyt?