Add a public initializer to RenderContentMetadata

[patshaughnessy]

Bug/issue #, if applicable: rdar://164210651

Summary

RenderContentMetadata, which is part of the Render JSON schema, doesn’t have a public initializer. This prevents other applications linking to Swift DocC from creating new metadata instances. This change adds a public initializer.

Dependencies

None.

Testing

Write a small Swift CLI executable program that links to Swift DocC, and then test that you can create an instance of RenderContentMetadata using this new public initializer.

let package = Package(
    name: "CreateRenderMetadata",
    platforms: [.macOS(.v15) ],
    dependencies: [
      .package(url: "[email protected]:patshaughnessy/swift-docc.git", branch: "r164210651-add-public-initializer-RenderContentMetadata"),
    ],
    targets: [
        .executableTarget(
            name: "CreateRenderMetadata",
            dependencies: [
                .product(name: "SwiftDocC", package: "swift-docc")
            ]
        ),
    ]
)

import SwiftDocC

@main
struct CreateRenderMetadata {
    static func main() {
        print("Hello, world!")
        let metadata = RenderContentMetadata()
        print(metadata)
    }
}

Checklist

Make sure you check off the following items. If they cannot be completed, provide a reason.

• Added tests
• Ran the ./bin/test script and it succeeded

[patshaughnessy]

@swift-ci please test