Component Docs Generation is platform dependent

[pront]

Summary

Configuration options behind features flags are compiled away when the feature is off.
When make generate-component-docs is run, the config options are removed from the docs.

Example

https://github.com/vectordotdev/vector/pull/22033/files#r1914968929

Proposed Solutions

1. Show all configuration options on all platforms but produce an error during runtime if they are used.
2. Generate static docs per platform.
3. Draw inspiration from rustdoc and #[cfg(doc)]. For example, see the Available on Unix only. label in https://doc.rust-lang.org/std/os/unix/fs/fn.symlink.html.