Add instructions to README

README.md

@@ -1,5 +1,9 @@
+[![Build Status](https://travis-ci.com/AlchemyCMS/alchemy-dragonfly-s3.svg?branch=master)](https://travis-ci.com/AlchemyCMS/alchemy-dragonfly-s3)
+
 # AlchemyCMS AWS S3
 
+Provides a `Alchemy::Picture.url_class` and `Alchemy::PictureThumb.generator_class` for Alchemy pictures stored on Amazon AWS S3.
+
 ## Installation
 
 Add this line to your application's Gemfile:
@@ -8,10 +12,48 @@ Add this line to your application's Gemfile:
 gem 'alchemy-dragonfly-s3', github: 'AlchemyCMS/alchemy-dragonfly-s3'
 ```
 
+For now you also need a special AlchemyCMS branch
+
+```ruby
+gem 'alchemy_cms', github: 'tvdeyen/alchemy_cms', branch: 'remote-images'
+```
+
 And then execute:
 
 ```
-$ bundle
+$ bundle install
+```
+
+Install the picture thumbs migration from Alchemy 5.1
+
+```
+$ bin/rake alchemy:install:migrations
+$ bin/rake db:migrate
+```
+
+## Setup
+
+Configure a S3 datastore for Dragonfly
+
+```ruby
+# config/initializers/dragonfly
+
+require "dragonfly/s3_data_store"
+
+...
+
+Dragonfly.app(:alchemy_pictures).configure do
+  plugin :imagemagick
+  plugin :svg
+
+  datastore :s3,
+    bucket_name: ENV.fetch("ALCHEMY_S3_BUCKET_NAME"),
+    access_key_id: ENV.fetch("ALCHEMY_S3_ACCESS_KEY_ID"),
+    secret_access_key: ENV.fetch("ALCHEMY_S3_SECRET_ACCESS_KEY"),
+    region: ENV.fetch("ALCHEMY_S3_REGION")
+end
+
+...
 ```
 
 ## License