docs: wordsmithed module definitions for the top-level lib docs

Author: naomiblack

lib/directive/module.dart

@@ -1,14 +1,14 @@
- /**
- * Directives for [angular.dart](#angular/angular), a web framework for Dart. A directive attaches
- * a specified behavior to a DOM element.
+/**
+ * All of the core directives available in Angular. This library is included as part of [angular
+ * .dart](#angular/angular).
  *
- * This library is included as part of [angular.dart](#angular/angular). It provides all of
- * the core Directives available in Angular. You can extend Angular by writing your own directives
- * and providing them as part of a custom library.
+ * A directive attaches a specified behavior to a DOM element. You can extend Angular by writing
+ * your own directives and providing them as part of a custom library.
  *
  * Directives consist of a class specifying the behavior, and a directive annotation (such as a
- * [Decorator](#angular-core-annotation.Decorator) or a [Component](#angular-core-annotation.Component)) that
-  * describes when the behavior should be applied.
+ * [Decorator](#angular-core-annotation.Decorator) or a
+ * [Component](#angular-core-annotation.Component)) that describes when the behavior should be
+ * applied.
  *
  * For example:
  *

lib/formatter/module.dart

@@ -1,18 +1,18 @@
 /**
- * Formatters for [angular.dart](#angular/angular), a web framework for Dart. A formatter is a
- * pure function that performs a transformation on input data from an expression.
+ * All of the core formatters available in Angular. This library is included as part of
+ * [angular.dart](#angular/angular).
  *
- * This library is included as part of [angular.dart](#angular/angular). It provides all of
- * the core formatters available in Angular. You can extend Angular by writing your own formatters
- * and providing them as part of a custom library. See the @[Formatter](#angular-core-annotation
- * .Formatter) class annotation for more detail.
+ * A formatter is a pure function that performs a transformation on input data from an expression.
+ * You can extend Angular by writing your own formatters and providing them as part of a custom
+ * library. See the @[Formatter](#angular-core-annotation .Formatter) class annotation for more
+ * detail.
  *
  * Formatters are typically used within `{{ }}` to
  * convert data to human-readable form. They may also be used inside repeaters to transform arrays.
  *
  * For example:
  *
- *     {{ expression | json }}
+ *     {{ expression | uppercase }}
  *
  * or, in a repeater:
  *

lib/formatter/module_internal.dart

@@ -22,8 +22,9 @@ part 'stringify.dart';
 /**
  * This module registers all the Angular formatters.
  *
- * When instantiating an Angular application through applicationFactory,
- * FormatterModule is automatically included.
+ * When instantiating an Angular application through
+ * [applicationFactory](#angular-app-factory@id_applicationFactory), FormatterModule is
+ * automatically included.
  */
 class FormatterModule extends Module {
   FormatterModule() {