Add "Sigma Computing" API

[dhyxy]

Format: openapi
Official: true
Url: https://help.sigmacomputing.com/openapi/sigma-computing-public-rest-api.json
Name: Sigma Computing
Category: data
Logo: https://pbs.twimg.com/profile_images/1672270090455359488/I43qeVBP_400x400.jpg