Add meta description for introduction documents

docs/introduction/di_in_python.rst

@@ -1,6 +1,13 @@
 Dependency injection and inversion of control in Python
 -------------------------------------------------------
 
+.. meta::
+   :keywords: Python,DI,Dependency injection,IoC,Inversion of Control
+   :description: This article describes benefits of dependency injection and 
+                 inversion of control for Python applications. Also it 
+                 contains some Python examples that show how dependency 
+                 injection and inversion could be implemented.
+
 History
 ~~~~~~~
 

docs/introduction/index.rst

@@ -1,6 +1,12 @@
 Introduction
 ============
 
+.. meta::
+   :keywords: Python,DI,Dependency injection,IoC,Inversion of Control
+   :description: Current section of documentation is designed to give some 
+                 overview about dependency injection pattern, inversion of 
+                 control principle and "Dependency Injector" framework.
+
 Current section of documentation is designed to give some overview about 
 dependency injection pattern, inversion of control principle and 
 *Dependency Injector* framework.

docs/introduction/key_features.rst

@@ -1,6 +1,12 @@
 Key features of Dependency Injector
 -----------------------------------
 
+.. meta::
+   :keywords: Python,DI,Dependency injection,IoC,Inversion of Control
+   :description: This article describes key features of "Dependency Injector" 
+                 framework. It also provides some cases and recommendations 
+                 about usage of "Dependency Injector" framework.
+
 *Dependency Injector* is a dependency injection framework for Python projects. 
 It was designed to be unified, developer-friendly tool for managing any kind
 of Python objects and their dependencies in formal, pretty way.

docs/introduction/structure.rst

@@ -1,6 +1,13 @@
 Structure of Dependency Injector
 --------------------------------
 
+.. meta::
+   :keywords: Python,DI,Dependency injection,IoC,Inversion of Control
+   :description: This article describes "Dependency Injector" framework 
+                 components and their interaction between each other. 
+                 Catalogs, providers and injections are the former 
+                 components of the framework.
+
 Current section describes *Dependency Injector* main entities and their 
 interaction between each other.
 

docs/introduction/what_is_di.rst

@@ -1,6 +1,15 @@
 What is dependency injection and inversion of control?
 ------------------------------------------------------
 
+.. meta::
+   :keywords: Python,DI,Dependency injection,IoC,Inversion of Control
+   :description: This article provides definition of dependency injection, 
+                 inversion of control and dependency inversion. It contains 
+                 example code in Python that is refactored to be following 
+                 inversion of control principle and then enhanced by 
+                 inversion of control container based on "Dependency Injector" 
+                 declarative catalog.
+
 Definition
 ~~~~~~~~~~