Is fileMetadataFiles supported?

[mhsimkin]

The docfx.json config file allows a build property of fileMetadataFiles. Has this been implemented? When I search the code base, I see the property defined in BuildJsonConfig.cs, however, I have not been able to find any other usage in the code base.

I have some metadata that I want to change on a per section basis and I was hoping to just point to the supplementary metadata files in each section.

Thanks

-marc