Update README.md for branches

fix #974

CHANGELOG.md

@@ -3,6 +3,7 @@ Version 153:
 * Remove BOOST_VERSION checks
 * Use make_error_code for setting an error_code from errc
 * Use boost::winapi::GetLastError() consistently 
+* Update README.md for branches
 
 --------------------------------------------------------------------------------
 

README.md

@@ -8,26 +8,13 @@ Branch      | Linux/OSX | Windows | Coverage | Documentation | Matrix
 [master](https://github.com/boostorg/beast/tree/master)   | [![Build Status](https://travis-ci.org/boostorg/beast.svg?branch=master)](https://travis-ci.org/boostorg/beast)  | [![Build status](https://ci.appveyor.com/api/projects/status/g0llpbvhpjuxjnlw/branch/master?svg=true)](https://ci.appveyor.com/project/vinniefalco/beast/branch/master)   | [![codecov](https://codecov.io/gh/boostorg/Beast/branch/master/graph/badge.svg)](https://codecov.io/gh/boostorg/beast/branch/master)   | [![Documentation](https://img.shields.io/badge/documentation-master-brightgreen.svg)](http://www.boost.org/doc/libs/master/libs/beast/doc/html/index.html)  | [![Matrix](https://img.shields.io/badge/matrix-master-brightgreen.svg)](http://www.boost.org/development/tests/master/developer/beast.html)
 [develop](https://github.com/boostorg/beast/tree/develop) | [![Build Status](https://travis-ci.org/boostorg/beast.svg?branch=develop)](https://travis-ci.org/boostorg/beast) | [![Build status](https://ci.appveyor.com/api/projects/status/g0llpbvhpjuxjnlw/branch/develop?svg=true)](https://ci.appveyor.com/project/vinniefalco/beast/branch/develop) | [![codecov](https://codecov.io/gh/boostorg/Beast/branch/develop/graph/badge.svg)](https://codecov.io/gh/boostorg/beast/branch/develop) | [![Documentation](https://img.shields.io/badge/documentation-develop-brightgreen.svg)](http://www.boost.org/doc/libs/develop/libs/beast/index.html) | [![Matrix](https://img.shields.io/badge/matrix-develop-brightgreen.svg)](http://www.boost.org/development/tests/develop/developer/beast.html)
 
-# Important Notice About Versions
-
-The version of Beast at the tip of the **master** and **develop** branches
-requires the latest version of Boost.Asio. Specifically it requires the
-developmental version of Boost.Asio located at the **master** branch of
-the Boost.Asio repository.
-
-The latest Beast cannot be compiled against Boost 1.65.1 and earlier. To
-use Boost 1.65.1 and earlier with Beast it is necessary to use Beast
-version 124, which is available here: https://github.com/boostorg/beast/tree/v124
-
-This situation is temporary until Boost 1.66.0 is released, where Beast and
-Asio will work correctly with each other within the monolithic Boost release.
-
 ## Contents
 
 - [Introduction](#introduction)
 - [Appearances](#appearances)
 - [Description](#description)
 - [Requirements](#requirements)
+- [Git Branches](#branches)
 - [Building](#building)
 - [Usage](#usage)
 - [License](#license)
@@ -87,6 +74,25 @@ One of these components is required in order to build the tests and examples:
 * Properly configured bjam/b2
 * CMake 3.5.1 or later (Windows only)
 
+## Branches
+
+The official repository contains the following branches:
+
+* [**master**](https://github.com/boostorg/beast/tree/master) This
+  holds the most recent snapshot with code that is known to be stable.
+
+* [**develop**](https://github.com/boostorg/beast/tree/develop) This
+  holds the most recent snapshot. It may contain unstable code.
+
+Each of these branches requires a corresponding Boost branch and
+all of its subprojects. For example, if you wish to use the **master**
+branch version of Beast, you should clone the Boost superproject,
+switch to the **master** branch in the superproject and acquire
+all the Boost libraries corresponding to that branch including Beast.
+
+Or, to use the latest shipping version of Beast, simply use it
+from the corresponding distribution of Boost.
+
 ## Building
 
 Beast is header-only. To use it just add the necessary `#include` line