Add README and LICENSE

LICENSE

@@ -0,0 +1,19 @@
+Copyright (c) 2015 Code Climate, Inc.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.

README.md

@@ -1 +1,68 @@
 # codeclimate-duplication
+
+`codeclimate-duplication` is an engine that wraps [flay] and supports Ruby,
+Python, JavaScript, and PHP. You can run it in the command line using the Code
+Climate CLI, or on our [hosted analysis platform][codeclimate].
+
+[codeclimate]: https://codeclimate.com/dashboard
+
+## Installation
+
+1. If you haven't already, [install the Code Climate CLI][cli]
+2. Run `codeclimate engines:enable duplication`. This command both installs the
+  engine and enables it in your `.codeclimate.yml` file.
+3. You're ready to analyze! Browse into your project's folder and run
+  `codeclimate analyze`.
+
+[cli]: https://github.com/codeclimate/codeclimate
+
+## Configuring
+
+You can add the following to your `.codeclimate.yml` to get started with the
+duplication engine.
+
+```yaml
+engines:
+  duplication:
+    enabled: true
+    config:
+      languages:
+        YOUR_LANGUAGE:
+```
+
+This will tell Code Climate to run the duplication engine with `YOUR_LANGUAGE`.
+You can also specify a `paths` array under `YOUR_LANGUAGE` which use Ruby's
+[`Dir.glob`][glob] format.
+
+For example, all JavaScript and JSX files:
+
+```yaml
+engines:
+  duplication:
+    enabled: true
+    config:
+      languages:
+        javascript:
+          paths:
+            - "**/*.js"
+            - "**/*.jsx"
+```
+
+[glob]: http://ruby-doc.org/core-1.9.3/Dir.html#method-c-glob
+
+You can also specify the mass threshold which is what determines how much "mass"
+a block of code needs before it's checked for duplication. This varies from
+language to language with higher numbers needing more mass to trigger a check
+and lower numbers needing less mass.
+
+For example you could tell the engine to check only very large blocks of code:
+
+```
+engines:
+  duplication:
+    enabled: true
+    config:
+      languages:
+        javascript:
+          mass_threshold: 300
+```