pkg/docgen: removed yaml and append output support

pkg/docgen/lib/docgen.dart

Index: pkg/docgen/lib/docgen.dart
diff --git a/pkg/docgen/lib/docgen.dart b/pkg/docgen/lib/docgen.dart
index f56bf694e7c26964fb4aae8e8949adb1154b33cf..f35037c33ae9c5afaf3f974f3f71c54e1d453d0a 100644
--- a/pkg/docgen/lib/docgen.dart
+++ b/pkg/docgen/lib/docgen.dart
@@ -38,8 +38,7 @@ export 'src/package_helpers.dart' show packageNameFor;
 ///
 /// Returned Future completes with true if document generation is successful.
 Future<bool> docgen(List<String> files, {String packageRoot,
-    bool outputToYaml: false, bool includePrivate: false,
-    bool includeSdk: false, bool parseSdk: false, bool append: false,
+    bool includePrivate: false, bool includeSdk: false, bool parseSdk: false,
     String introFileName: '', String out: gen.DEFAULT_OUTPUT_DIRECTORY,
     List<String> excludeLibraries: const [],
     bool includeDependentPackages: false, bool compile: false,
@@ -49,8 +48,8 @@ Future<bool> docgen(List<String> files, {String packageRoot,
   if (!noDocs) {
     viewer.ensureMovedViewerCode();
     result = gen.generateDocumentation(files, packageRoot: packageRoot,
-        outputToYaml: outputToYaml, includePrivate: includePrivate,
-        includeSdk: includeSdk, parseSdk: parseSdk, append: append,
+        includePrivate: includePrivate,
+        includeSdk: includeSdk, parseSdk: parseSdk,
         introFileName: introFileName, out: out,
         excludeLibraries: excludeLibraries,
         includeDependentPackages: includeDependentPackages,