Make templates appear where they are defined. (#1816)

* Make templates appear where they are defined.

* Rebuild test package docs

* Test tweak

Author: jcollins-g

lib/src/model.dart

@@ -4251,7 +4251,7 @@ abstract class ModelElement extends Canonicalization
         multiLine: true);
     return rawDocs.replaceAllMapped(templateRegExp, (match) {
       packageGraph._addMacro(match[1].trim(), match[2].trim());
-      return "";
+      return "{@macro ${match[1].trim()}}";
     });
   }
 

test/model_test.dart

@@ -719,7 +719,7 @@ void main() {
 
     test("renders a macro within the same comment where it's defined", () {
       expect(withMacro.documentation,
-          equals("Macro method\n\n\nFoo macro content\nMore docs"));
+          equals("Macro method\n\nFoo macro content\nMore docs"));
     });
 
     test("renders a macro in another method, not the same where it's defined",

testing/test_package/lib/example.dart

@@ -337,7 +337,6 @@ class Dog implements Cat, E {
   /// Foo macro content
   /// {@endtemplate}
   ///
-  /// {@macro foo}
   /// More docs
   void withMacro() {}