Update readme

Author: wanze

DOCUMENTATION.md

@@ -15,6 +15,7 @@
 The `2.x` major version introduces several backwards compatibility breaks. The amount of required manual update steps
 depends on how many features were used. The following list _should_ cover the most important changes: 
 
+* Your template engine must support the `2.x` version. Check the available template engines in the [readme](README.md#available-template-engines).
 * The API variable `$factory` is no longer available. Use `$modules->get('TemplateEngineFactory')` to get an instance of
 the `\ProcessWire\TemplateEngineFactory` class.
 * The factory has a new configuration `templates_path`, indicating where the engine's templates are stored. This config

README.md

@@ -1,7 +1,7 @@
 # Template Engine Factory
 
-[![Build Status](https://travis-ci.org/wanze/TemplateEngineFactory.svg?branch=next)](https://travis-ci.org/wanze/TemplateEngineFactory)
-[![StyleCI](https://github.styleci.io/repos/21270731/shield?branch=next)](https://github.styleci.io/repos/21270731)
+[![Build Status](https://travis-ci.org/wanze/TemplateEngineFactory.svg?branch=master)](https://travis-ci.org/wanze/TemplateEngineFactory)
+[![StyleCI](https://github.styleci.io/repos/21270731/shield?branch=master)](https://github.styleci.io/repos/21270731)
 [![License: MIT](https://img.shields.io/badge/License-MIT-blue.svg)](https://opensource.org/licenses/MIT)
 [![ProcessWire 3](https://img.shields.io/badge/ProcessWire-3.x-orange.svg)](https://github.com/processwire/processwire)
 
@@ -14,7 +14,7 @@ via template engine and encourages to separate logic from markup by implementing
 > Version `2.x` of this module differs from the `1.x` version in many ways. Modules providing template engines _must_ be
 installed with Composer. Twig is currently the only template engine implemented for the `2.x` major version. Please
 take a look at the [update guide](DOCUMENTATION.md#updating-from-1x-to-2x), as the new version introduces backwards
-compatibility breaks.
+compatibility breaks. The `1.x` version of the module is available on the [1.x branch](https://github.com/wanze/TemplateEngineFactory/tree/1.x).
 
 ## Requirements