Not clear about the behavior on OpenAPI__ApiKey configuration running in Azure Function App

**Describe the issue**
In version 1.3, the current `ApiKey` in Azure Function configuration doing nothing. The `code` will always be the function key, and it could be authenticated by the `x-function-key` in the header. However, in [doc](https://github.com/Azure/azure-functions-openapi-extension/blob/main/docs/openapi.md#Configure-Authorization-Level) it says we MUST specify the `ApiKey`.

Authenticated by the `x-function-key` with the function key is secure. It is what I like. However, it is different to the document
and it is **confusing**.

I have seen a related [issue](https://github.com/Azure/azure-functions-openapi-extension/issues/382) #383. I only see that [fix](https://github.com/Azure/azure-functions-openapi-extension/pull/383) fixing the `SwaggerUI` file.
Is it designed to only fix the swagger ui endpoint `ApiKey` behavior? Or it will affect the OpenAPI document endpoint `ApiKey` as well.

It is confusing every developer who is trying to deploy their function. The current documentation wastes our time to figure out what is going on and what should be the bug and correct behavior for the `OpenAPI__ApiKey` configuration.

**To Reproduce**
Steps to reproduce the behavior:
1. Deploy the azure function.
2. Specify the `"OpenApi__AuthLevel__Document" = "Function"` and (NOT specify or specify `OpenApi_ApiKey` to any value) in configuration.
3. Using the value specify in the `OpenApi__ApiKey` configuration to authenticate from either Url Query `code` or header `x-function-api` will response `401`. Instead, using function key in either Url Query `code` or header `x-function-key` will be `200`.

**Expected behavior**
Please remove the "Make sure that you MUST provide the OpenApi__AuthKey value, if you choose the OpenApi__AuthLevel__Document value other than Anonymous" in the document.
Documenting that: Without `OpenApi__ApiKey` configuration in deployed function, it will auto use the Azure Function Key to authenticate the OpenApi document endpoint, if the `OpenApi__AuthLevel__Document` is other than `Anonymous`.