Add contributing guide

CONTRIBUTING.md

@@ -0,0 +1,34 @@
+Generally, Finch follows a standard [fork and pull][0] model for contributions via GitHub pull requests. Thus, the
+_contributing process_ looks as follows:
+
+1. [Write code](#write-code)
+2. [Write tests](#write-tests)
+3. [Write docs](#write-docs)
+4. [Submit a PR](#submit-a-pr)
+
+## Write Code
+Finch follows [Effective Scala][1] code style guide. When in doubt, look around the codebase and see how it's done elsewhere.
+
+* Code and comments should be formatted to a width no greater than 120 columns
+* Files should be exempt of trailing spaces
+
+## Write Tests
+Finch uses [ScalaTest][2] with the following settings:
+
+* Every test should be a `FlatSpec` with `Matchers` mixed in
+* An assertion should be done with `x shouldBe y`
+* Exceptions should be intercepted with `an [Exception] should be thrownBy x`
+
+## Write Docs
+Write clean and simple docs in the `docs.md` file.
+
+## Submit a PR
+
+* PR should be submitted from a separate branch (use `git checkout -b "fix-133"`)
+* PR should contain only one commit (use `git commit --amend` and `git --force push`)
+* PR should not decrease the code coverage more than by 1%
+* PR's comment message should use present tense and be capitalized properly (i.e., `Add tests for RequestReader`)
+
+[0]: https://help.github.com/articles/using-pull-requests/
+[1]: http://twitter.github.io/effectivescala/
+[2]: http://www.scalatest.org/

README.md

@@ -62,7 +62,7 @@ Documentation
 Contacts
 --------
 
-* Use a Gitter room for questions like _"How do I ..."_ [![Gitter](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/finagle/finch?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+* Most of the discussions and announcements are happen at [![Gitter](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/finagle/finch?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 
 Adopters
 --------
@@ -71,6 +71,16 @@ Adopters
 * [Sabre Labs](http://sabrelabs.com)
 * *Submit a pull-request to include your company/project into the list*
 
+Contributing
+------------
+
+There are plenty of ways to contribute into Finch:
+
+* Give it a star
+* Join the [Gitter](https://gitter.im/finagle/finch) room and give a hand in answering users' questions
+* [Submit a PR](CONTRIBUTING.md)
+* Wear a [Finch T-Shirt](http://www.redbubble.com/people/vkostyukov/works/13277123-finch-io-rest-api-with-finagle?p=t-shirt)
+
 License
 -------