Rewrite contributing guidelines

CONTRIBUTING.md

@@ -1,20 +1,51 @@
-Contributing
-============
+Contributing to Chart.js
+========================
 
-New contributions to the library are welcome, just a couple of guidelines:
+Contributions to Chart.js are welcome and encouraged, but please have a look through the guidelines in this document before raising an issue, or writing code for the project.
 
- * Tabs for indentation, not spaces please.
- * Please ensure you're changing the individual files in /src, not the concatenated output in the Chart.js file in the root of the repo.
- * Please check that your code will pass jshint code standards, `gulp jshint` will run this for you.
- * Please keep pull requests concise, and document new functionality in the relevant .md file.
- * Consider whether your changes are useful for all users, or if creating a Chart.js extension would be more appropriate.
- * Please avoid committing in the build Chart.js & Chart.min.js file, as it causes conflicts when merging.
- 
-New Chart Types
-===============
 
-Chart.js is designed to be modular. See http://www.chartjs.org/docs/#advanced-usage-writing-new-chart-types
+Using issues
+------------
 
-All discussion of new chart types (horizontal bar charts, X-Y scatter plot, etc.) should be done in the Chart.js Google Group at https://groups.google.com/forum/#!forum/chartjs-user-discussion This will get the most exposure for getting people to help define requirements, complete programming and documentation of your vision.
+The [issue tracker](https://github.com/nnnick/Chart.js/issues) is the preferred channel for reporting bugs, requesting new features and submitting pull requests.
 
-Please do not request new chart types in the project issues. Fully implemented, documented, and useful new charts may be maintained in a new repository. Later, we may add a link to selected external repositories from this project.
+If you're suggesting a new chart type, please take a look at [writing new chart types](https://github.com/nnnick/Chart.js/blob/master/docs/06-Advanced.md#writing-new-chart-types) in the documentation, and some of the [community extensions](https://github.com/nnnick/Chart.js/blob/master/docs/06-Advanced.md#community-extensions) that have been created already.
+
+To keep the library lightweight for everyone, it's unlikely we'll add many more chart types to the core of Chart.js, but issues are a good medium to design and spec out how new chart types could work and look.
+
+Please do not use issues for support requests. For help using Chart.js, please take a look at the [`chartjs`](http://stackoverflow.com/questions/tagged/chartjs) tag on Stack Overflow.
+
+
+Reporting bugs
+--------------
+
+Well structured, detailed bug reports are hugely valuable for the project.
+
+Guidlines for reporting bugs:
+
+ - Check the issue search to see if it has already been reported
+ - Isolate the problem to a simple test case
+ - Provide a demonstration of the problem on [jsbin](http://jsbin.com) or similar
+
+Please provide any additional details associated with the bug, if it's browser of screen density specific, or only happens with a certain configuration or data.
+
+
+Pull requests
+-------------
+
+Clear, concise pull requests are excellent at continuing the projects community driven growth. But please review the guidelines below before starting work on the project.
+
+Guidlines:
+
+ - Please ask before starting significant work on a pull request to check it's a change within the project scope, and isn't a duplicate effort
+ - Please make changes to the files in [`/src`](https://github.com/nnnick/Chart.js/tree/master/src), not `Chart.js` or `Chart.min.js` in the repo root directory
+ - Tabs for indentation, not spaces please.
+ - If adding new functionality, please also update the relevant `.md` file in [`/docs`](https://github.com/nnnick/Chart.js/tree/master/docs)
+ - Please make your commits in logical sections with clear commit messages
+ - Please avoid committing in the build Chart.js & Chart.min.js file, as it may cause conflicts when merging back
+
+
+License
+-------
+
+By contributing your code, you agree to license your contribution under the [MIT license](https://github.com/nnnick/Chart.js/blob/master/LICENSE.md).