Rename files

Author: jcollins-g

lib/src/model/comment_processable.dart renamed to lib/src/model/documentation_comment.dart

@@ -7,7 +7,7 @@ export 'canonicalization.dart';
 export 'categorization.dart';
 export 'category.dart';
 export 'class.dart';
-export 'comment_processable.dart';
+export 'documentation_comment.dart';
 export 'constructor.dart';
 export 'container.dart';
 export 'container_member.dart';

lib/src/model/model.dart

@@ -16,7 +16,7 @@ import 'package:analyzer/src/dart/element/member.dart'
 import 'package:collection/collection.dart';
 import 'package:dartdoc/src/dartdoc_options.dart';
 import 'package:dartdoc/src/element_type.dart';
-import 'package:dartdoc/src/model/comment_processable.dart';
+import 'package:dartdoc/src/model/documentation_comment.dart';
 import 'package:dartdoc/src/model/feature_set.dart';
 import 'package:dartdoc/src/model/model.dart';
 import 'package:dartdoc/src/model_utils.dart' as utils;