add todo regarding implementation of AutomaticCurationTests.testAutomaticTopic()

Author: theMomax

Tests/SwiftDocCTests/Infrastructure/AutomaticCurationTests.swift

@@ -19,6 +19,9 @@ class AutomaticCurationTests: XCTestCase {
         let decoder = JSONDecoder()
 
         for kind in AutomaticCuration.groupKindOrder where kind != .module {
+            // TODO: Synthesize appropriate `swift.extension` symbols that get transformed into
+            // the respective internal symbol kinds as defined by `ExtendedTypeFormatTransformation`
+            // and remove decoder injection logic from `DocumentationContext` and `SymbolGraphLoader`
             if !SymbolGraph.Symbol.KindIdentifier.allCases.contains(kind) {
                 decoder.register(symbolKinds: kind)
             }