Support compiler directives or similar mechanism

[dfeinzimer]

Feature Name

Documentation availability

Description

Add support for compiler directives like #if targetEnvironment(_) or a similar mechanism for conditionally including lines of text in built documentation to prevent "'symbol' doesn't exist at .." warnings when building doc for different targets.

Motivation

Prevent warnings for unavailable symbols on the targeted platform when building documentation.

Importance

Allows building documentation for all platforms without triggering any "doesn't exist" warnings.

Alternatives Considered

No response