Support for expanding embedded structs

Hello everyone! I am from Prometheus-Operator 👋

We want to use `crd-ref-docs` in Prometheus-Operator for API reference. But, we are currently facing a problem while testing it 😫 . There is a struct called `ProxyConfig` that does not expand while generating the API-reference and looks like [this](https://deploy-preview-136--sleepy-hopper-0fdb6b.netlify.app/docs/api-reference/elastic-api/#proxyconfig) in the docs. I believe that `crd-ref-docs` cannot expand embedded structs. Here is the [link](https://github.com/prometheus-operator/prometheus-operator/blob/9be68efafca772687346ffa8b8cc0cbeba88d1e7/pkg/apis/monitoring/v1/types.go#L93) to the `ProxyConfig` struct code.

I want assistance with this if possible.