Tweak generics in renderable directive convertible

Author: ethan-kusters

Sources/SwiftDocC/Model/Rendering/RenderContentConvertible.swift

@@ -11,9 +11,7 @@
 import Foundation
 import Markdown
 
-protocol RenderableDirectiveConvertible: AutomaticDirectiveConvertible where DirectiveType == Self {
-    associatedtype DirectiveType
-    
+protocol RenderableDirectiveConvertible: AutomaticDirectiveConvertible {
     func render(with contentCompiler: inout RenderContentCompiler) -> [RenderContent]
 }
 
@@ -22,7 +20,7 @@ extension RenderableDirectiveConvertible {
         _ blockDirective: BlockDirective,
         with contentCompiler: inout RenderContentCompiler
     ) -> [RenderContent] {
-        guard let directive = DirectiveType.init(
+        guard let directive = Self.init(
             from: blockDirective,
             for: contentCompiler.bundle,
             in: contentCompiler.context