Updating main README file

Author: Krasimir Tsonev

README.md

@@ -4,26 +4,43 @@
 
 ## Content
 
-* [Introduction](./book/chapter-1/README.md)
+* [In brief](chapter-1/README.md)
 
 ### Foundation
 
 * [Communication](./book/chapter-2/README.md)
+  * [Input](./book/chapter-2/README.md#input)
+  * [Output](./book/chapter-2/README.md#output)
 * [Event handlers](./book/chapter-3/README.md)
 * [Composition](./book/chapter-4/README.md)
+  * [Using React's children API](./book/chapter-4/README.md#using-reacts-children-api)
+  * [Passing a child as a prop](./book/chapter-4/README.md#passing-a-child-as-a-prop)
+  * [Higher-order component](./book/chapter-4/README.md#higher-order-component)
+  * [Function as a children, render prop](./book/chapter-4/README.md#function-as-a-children-render-prop)
 * [Controlled and uncontrolled inputs](./book/chapter-5/README.md)
 * [Presentational and container components](./book/chapter-6/README.md) 
 
 ### Data flow
 
 * [One direction data flow](./book/chapter-7/README.md)
 * [Flux](./book/chapter-8/README.md)
+  * [Flux architecture and its main characteristics](./book/chapter-8/README.md#flux-architecture-and-its-main-characteristics)
+  * [Implementing a Flux architecture](./book/chapter-8/README.md#implementing-a-flux-architecture)
 * [Redux](./book/chapter-9/README.md)
+  * [Redux architecture and its main characteristics](./book/chapter-9/README.md#redux-architecture-and-its-main-characteristics)
+  * [Simple counter app using Redux](./book/chapter-9/README.md#simple-counter-app-using-redux)
 
 ### MISC
 
 * [Dependency injection](./book/chapter-10/README.md)
+  * [Using React's context (prior v. 16.3)](./book/chapter-10/README.md#using-reacts-context-prior-v-163)
+  * [Using React's context (v. 16.3 and above)](./book/chapter-10/README.md#using-reacts-context-v-163-and-above)
+  * [Using the module system](./book/chapter-10/README.md#using-the-module-system)
 * [Styling](./book/chapter-11/README.md)
+  * [The good old CSS class](./book/chapter-11/README.md#the-good-old-css-class)
+  * [Inline styling](./book/chapter-11/README.md#inline-styling)
+  * [CSS modules](./book/chapter-11/README.md#css-modules)
+  * [Styled-components](./book/chapter-11/README.md#styled-components)
 * [Integration of third-party libraries](./book/chapter-12/README.md)