Factor-pricing-model-risk-model

Feature

* Support dask engine ([`972973f`](https://github.com/factorpricingmodel/factor-pricing-model-risk-model/commit/972973fa3cc86786bf9988eb214aa713863cf383))

Fix

* Use validity in rolling fit ([`087939b`](https://github.com/factorpricingmodel/factor-pricing-model-risk-model/commit/087939b9c07a96242d3f7c6ff39a8060d801b2c1))

Documentation

* Update numpy backend engine notebook ([`5037603`](https://github.com/factorpricingmodel/factor-pricing-model-risk-model/commit/50376039629619cdd5396e74f598d1ae769e2369))

Fix

* Convert y into numpy engine array ([`e92fc34`](https://github.com/factorpricingmodel/factor-pricing-model-risk-model/commit/e92fc34d00c0f531be6c6d2b7d53f977d08c2b6e))

Feature

* Support setting the backend engine with environment variable ([`a40ee5c`](https://github.com/factorpricingmodel/factor-pricing-model-risk-model/commit/a40ee5cc42b3349fc96052d28568d01f666b313e))

Feature

* Support pytorch in engine ([`1d9eb07`](https://github.com/factorpricingmodel/factor-pricing-model-risk-model/commit/1d9eb07602cbdbefeef51f88f1a18bdb1ec26308))

Fix

* Use engine linalg in WLS ([`98ea2ed`](https://github.com/factorpricingmodel/factor-pricing-model-risk-model/commit/98ea2ed5946fb1fac619f68003312b83446884ae))

Documentation

* Fix syntax issue ([`cc8b9f5`](https://github.com/factorpricingmodel/factor-pricing-model-risk-model/commit/cc8b9f5c8d9936d7d6b53a2e743c3a473f4f6fa6))
* Fix lint ([`89a55c7`](https://github.com/factorpricingmodel/factor-pricing-model-risk-model/commit/89a55c7611e2a7abd59cda7e124903de10158df6))
* Add engine ([`7cd84d7`](https://github.com/factorpricingmodel/factor-pricing-model-risk-model/commit/7cd84d7620364ca6ed57ea01449ec9bd6410e241))
* Add numpy backend engine example ([`a81a2eb`](https://github.com/factorpricingmodel/factor-pricing-model-risk-model/commit/a81a2eb6f8e076626dd1bfd8da62ef64ee8d09cb))

Fix

* Revert forcing numpy array conversion ([`6676fef`](https://github.com/factorpricingmodel/factor-pricing-model-risk-model/commit/6676fefc7842e41c10ca735afccc241fad0d1d6e))