Update documentation

CONTRIBUTING.md

@@ -18,4 +18,4 @@ do this:
 
 This makes error messages and debugging simpler. The jsfiddle does this automatically.
 
-Sending a Pull Request? See our [guide to making dygraphs contributions](http://dygraphs.com/changes.html).
+Sending a Pull Request? See our [guide to making dygraphs contributions](/DEVELOP.md).

DEVELOP.md

@@ -0,0 +1,46 @@
+## dygraphs developer notes
+
+So you've made a change to dygraphs and would like to contribute it back to the open source project. Wonderful!
+
+This is a step-by-step guide explaining how to do it.
+
+### How-to
+
+To build dygraphs, run
+
+    gulp dist
+
+To run the tests, run:
+
+    gulp test
+
+To iterate on the code, open `tests/demo.html` (or one of the other demos) in your browser.
+
+To iterate on a unit test, change `it` to `it.only` in the Mocha test, change the browser from `PhantomJS` to `Chrome` (or whatever you like) in `auto_tests/karma.conf.js`, run
+
+    ./node_modules/karma/bin/karma start auto_tests/karma.conf.js
+
+and hit "DEBUG" in the Karma UI.
+
+### dygraphs style
+
+When making a change, please try to follow the style of the existing dygraphs code. This will make the review process go much more smoothly.
+
+A few salient points:
+
+1. We try to adhere to Google's [JS style guide][gstyle] and would appreciate it if you try to as well. This means:
+  *   No tabs! Indent using two spaces.
+  *   Use camelCase for variable and function names.
+  *   Limit lines to 80 characters.
+1.  If you've added a new feature, add a test for it (in the tests/ directory) or a gallery entry.
+1.  If you've added an option, document it in `dygraph-options-reference.js`. You'll get lots of warnings if you don't.
+1.  If you've fixed a bug or added a feature, add a unit test (in `auto_tests`) for it.
+
+Adding a unit test ensures that we won't inadvertently break your feature in the future. To do this, either add to an existing test in `auto_tests/tests` or create a new one.
+
+### Sending a Pull Request
+
+To make a change, you'll need to send a Pull Request. See GitHub's documentation [here][pr].
+
+[gstyle]: http://google-styleguide.googlecode.com/svn/trunk/javascriptguide.xml
+[pr]: http://help.github.com/send-pull-requests/

README.md

@@ -46,10 +46,14 @@ Learn more by reading [the tutorial](http://www.dygraphs.com/tutorial.html) and
 seeing demonstrations of what dygraphs can do in the
 [gallery](http://www.dygraphs.com/gallery).
 
-## Making Changes
-If you've made a change to dygraphs and would like to contribute it back to the
-community, please follow the [Guide to making dygraphs
-changes](http://dygraphs.com/changes.html).
+## Development
+
+To get going, clone the repo and run:
+
+    npm install
+    gulp dist
+
+Read more about the dygraphs development process in the [developer guide](/DEVELOP.md).
 
 ## License(s)
 dygraphs uses: