docs: add installation instructions and screenshot

CHANGELOG.md

@@ -1,5 +1,11 @@
 # Changelog
 
+## 1.1.1 (November 25, 2017)
+
+IMPROVEMENTS:
+
+- Add installation instructions and screenshot
+
 ## 1.1.0 (November 25, 2017)
 
 NEW FEATURES:

README.md

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