Clarify the use of `order_by` versus `order` in the inscription requests

[sabbyanandan]

While exploring https://docs.hiro.so/ordinals/list-of-inscriptions, as a user, I see order_by and order, and they both appear similar in functionality, but they aren't.

Moreover, the OpenAPI documentation for order_by reads as "Parameter to order results by". I don't know what parameters are acceptable.

When looking at the API calls from the Ordinals Explorer (see below), I notice order_by=genesis_block_height as an example, but it is not documented in the spec, nor can I find the list of supported parameters.

https://api.hiro.so/ordinals/v1/inscriptions?limit=20&offset=0&order=desc&order_by=genesis_block_height&rarity=rare

Is this all the genesis-typed parameters or others are possible?