Fix 404 links in REAMDE.md and add the missing CONTRIBUTING.md linked from the README

Author: mumoshu

CONTRIBUTING.md

@@ -0,0 +1,71 @@
+# How to Contribute
+
+CoreOS projects are [Apache 2.0 licensed](LICENSE) and accept contributions via
+GitHub pull requests.  This document outlines some of the conventions on
+development workflow, commit message formatting, contact points and other
+resources to make it easier to get your contribution accepted.
+
+# Certificate of Origin
+
+By contributing to this project you agree to the Developer Certificate of
+Origin (DCO). This document was created by the Linux Kernel community and is a
+simple statement that you, as a contributor, have the legal right to make the
+contribution. See the [DCO](DCO) file for details.
+
+# Email and Chat
+
+The project currently uses the general CoreOS email list and IRC channel:
+- Email: [coreos-dev](https://groups.google.com/forum/#!forum/coreos-dev)
+- IRC: #[coreos](irc://irc.freenode.org:6667/#coreos) IRC channel on freenode.org
+
+Please avoid emailing maintainers found in the MAINTAINERS file directly. They
+are very busy and read the mailing lists.
+
+## Getting Started
+
+- Fork the repository on GitHub
+- Read the [README](README.md) for build and test instructions
+- Play with the project, submit bugs, submit patches!
+
+## Contribution Flow
+
+This is a rough outline of what a contributor's workflow looks like:
+
+- Create a topic branch from where you want to base your work (usually master).
+- Make commits of logical units.
+- Make sure your commit messages are in the proper format (see below).
+- Push your changes to a topic branch in your fork of the repository.
+- Make sure the tests pass, and add any new tests as appropriate.
+- Submit a pull request to the original repository.
+
+Thanks for your contributions!
+
+### Format of the Commit Message
+
+We follow a rough convention for commit messages that is designed to answer two
+questions: what changed and why. The subject line should feature the what and
+the body of the commit should describe the why.
+
+```
+scripts: add the test-cluster command
+
+this uses tmux to setup a test cluster that you can easily kill and
+start for debugging.
+
+Fixes #38
+```
+
+The format can be described more formally as follows:
+
+```
+<subsystem>: <what changed>
+<BLANK LINE>
+<why this change was made>
+<BLANK LINE>
+<footer>
+```
+
+The first line is the subject and should be no longer than 70 characters, the
+second line is always blank, and other lines should be wrapped at 80 characters.
+This allows the message to be easier to read on GitHub as well as in various
+git tools.

README.md

@@ -230,7 +230,7 @@ The following links can be useful for development:
 
 ## Contributing
 
-Submit a PR to this repository, following the [contributors guide](../../CONTRIBUTING.md).
-The documentation is published from [this source](../../Documentation/kubernetes-on-aws.md).
+Submit a PR to this repository, following the [contributors guide](CONTRIBUTING.md).
+The documentation is published from [this source](Documentation/kubernetes-on-aws.md).