Create contributing guidelines

.github/CONTRIBUTING.md

@@ -0,0 +1,85 @@
+# How Can I Contribute?
+
+We're so glad you asked!
+
+**Table of Contents**
+
+[Reporting Bugs](#reporting-bugs)
+
+[Improving Documentation](#improving-documentation)
+
+[Contributing New Tasks](#contributing-new-tasks)
+* [Contributing New Tasks to the Existing Katas](#contributing-new-tasks-to-the-existing-katas)
+* [Contributing New Katas](#contributing-new-katas)
+
+[Style Guide](#style-guide)
+
+[Contributor License Agreement](#contributor-license-agreement)
+
+[Code of Conduct](#code-of-conduct)
+
+## Reporting Bugs
+
+If you think you've found a bug in one of the tasks, start by looking through [the existing issues](https://github.com/Microsoft/QuantumKatas/issues?q=is%3Aissue) in case it has already been reported (or it's not a bug at all). 
+
+If there are no issues describing the problem you found, [open a new issue](https://github.com/Microsoft/QuantumKatas/issues/new).
+
+You can also [create a pull request](https://help.github.com/articles/about-pull-requests/) to fix the bug directly, if it's very straightforward and is not worth the discussion (for example, a typo).
+
+## Improving Documentation
+
+Each kata has a README.md file with a brief description of the topic covered in the kata and a list of useful links on that topic. If you have come across a paper/tutorial/lecture which was really helpful for solving some of the kata's tasks, feel free to create a pull request to add it to the corresponding README file.
+
+## Contributing New Tasks
+
+Whether you want to contribute a new task to an existing kata or to create a completely new kata, start by opening an issue describing your intended contribution. 
+This way you'll get feedback on your idea faster and easier than if you go all the way to implementing it first.
+This will also ensure that you're not working on the same thing as somebody else.
+
+We're always happy to discuss new ideas and to offer advice, be it on the test harness implementation or on the best breakdown of a topic into tasks.
+
+### Contributing New Tasks to the Existing Katas
+
+Each kata is a sequence of tasks on the topic progressing from very simple to quite challenging. If you have an idea for a task which fits nicely in the sequence, filling a gap between other tasks or expanding the sequence with harder tasks, bring it forward!
+
+### Contributing New Katas
+
+We aim for the Quantum Katas to be a proper companion for any "Introduction to Quantum Computing" course, and eventually go beyond that.
+Obviously, there is a lot of work to be done to get there! 
+
+We welcome contributions of katas covering new topics. 
+We are keeping a list of topics we already have covered, topics people are working on, and topics we'd like to have covered in the future at [the Roadmap](https://github.com/Microsoft/QuantumKatas/wiki/Roadmap) wiki page. 
+This list is by no means complete or final; we will expand it as new topics come in.
+
+If you want to create a kata for some topic, start by checking the roadmap to see whether there is anybody already working on it (duplicating work is not fun). 
+If somebody is already working on this topic, you can try to find them (using the repository issues) and coordinate with them.
+If the topic you want is not claimed, or is not on the list, go ahead and let us know you'll be working on it by creating an issue.
+
+### Style Guide
+
+* We try to adhere to [the general Q# Style Guide](https://github.com/Microsoft/Quantum/blob/master/Docs/style-guide.md) in our Q# code. 
+* We also try to maintain a uniform style across the katas and most importantly within each kata. 
+  If you're adding a new task to an existing kata, it should be styled the same way as the rest of its tasks. 
+  If you're creating a new kata, model it after the style of the existing katas. 
+  This includes naming conventions, argument conventions, task description style etc.
+* Each task should be covered by a test which verifies the solution, and each task should be accompanied by a reference solution which allows this test to pass.
+* All code should build, and the tests should fail. Be careful not to carry this habit over to other projects, though!
+* Avoid code duplication within one kata as much as possible. Most katas have series of similar tasks which are covered with similar test code; 
+  it's usually better to extract this code into a generalized "framework" operation and use it in several tests than to duplicate it with small variations in each test.
+* Avoid platform-dependent code: all katas should work on Windows 10, macOS and Linux, and both in Visual Studio and in Visual Studio Code/command line.
+
+### Contributor License Agreement
+
+Most code contributions require you to agree to a
+Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us
+the rights to use your contribution. For details, visit https://cla.microsoft.com.
+
+When you submit a pull request, a CLA-bot will automatically determine whether you need to provide
+a CLA and decorate the PR appropriately (e.g., label, comment). Simply follow the instructions
+provided by the bot. You will only need to do this once across all repos using our CLA.
+
+### Code of Conduct
+
+This project has adopted the [Microsoft Open Source Code of Conduct](https://opensource.microsoft.com/codeofconduct/).
+For more information see the [Code of Conduct FAQ](https://opensource.microsoft.com/codeofconduct/faq/) or
+contact [opencode@microsoft.com](mailto:opencode@microsoft.com) with any additional questions or comments.

README.md

@@ -107,13 +107,9 @@ Press Ctrl + Shift + P (or ⌘ + Shift + P on macOS) to open the Palette and typ
 
 # Contributing
 
-This project welcomes contributions and suggestions.  Most contributions require you to agree to a
-Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us
-the rights to use your contribution. For details, visit https://cla.microsoft.com.
+This project welcomes contributions and suggestions.  For details, see [How Can I Contribute?](./CONTRIBUTING.md)
 
-When you submit a pull request, a CLA-bot will automatically determine whether you need to provide
-a CLA and decorate the PR appropriately (e.g., label, comment). Simply follow the instructions
-provided by the bot. You will only need to do this once across all repos using our CLA.
+# Code of Conduct
 
 This project has adopted the [Microsoft Open Source Code of Conduct](https://opensource.microsoft.com/codeofconduct/).
 For more information see the [Code of Conduct FAQ](https://opensource.microsoft.com/codeofconduct/faq/) or