docs: add installation instructions and screenshot

CHANGELOG.md

@@ -1,6 +1,6 @@
 # Changelog
 
-## 1.1.0
+## 1.1.0 (November 26, 2017)
 
 NEW FEATURES:
 
@@ -12,6 +12,7 @@ NEW FEATURES:
 IMPROVEMENTS:
 
 - Add example zone file using many possibilities offered by RFC 1035 syntax (even if this package does not highlight it correctly)
+- Add installation instructions and screenshot
 
 ## 1.0.0 (November 11, 2017)
 

README.md

@@ -2,6 +2,22 @@
 
 Adds basic syntax highlighting based on the [Sublime Text package](https://github.com/sixty4k/st2-zonefile) to zone files in Atom.
 
+![Screenshot](/screenshot.png?raw=true)
+
+## Installation
+
+Available as [Atom package](https://atom.io/packages/language-zonefile):
+
+```
+apm install language-zonefile
+```
+
+Or directly via git:
+
+```
+git clone https://github.com/cmur2/language-zonefile.git ~/.atom/packages/language-zonefile
+```
+
 ## License
 
 language-zonefile is licensed under the MIT License. See LICENSE for more information.