Asset Class "crypto_perp" being returned in /v2/Assets endpoint

**Describe the bug**
The /v2/assets endpoint returns at least one asset with the class set to 'crypto_perp'

**To Reproduce**
Steps to reproduce the behavior:
Go to https://paper-api.alpaca.markets/v2/assets?asset_class=crypto_perp

**Expected behavior**
This class should be returning 'crypto' (I think). Or if that's not right, and this is a different class of asset, we should define and explain what crypto_perp is somewhere in the documentation.