Update CONTRIBUTING.md

CONTRIBUTING.md

@@ -1,36 +1,44 @@
 # Contributing to Boats Animator
+
 Thank you for choosing to help improve Boats Animator!
 
 ## Setup
+
 1. Make sure [Git](https://git-scm.com/) and [Node.js](https://nodejs.org/) are installed on your computer.
 2. Fork this repository by pressing ![Fork](https://camo.githubusercontent.com/07b3944af53da32b0cffe98152c45c46431a82f0/687474703a2f2f6938312e73657276696d672e636f6d2f752f6638312f31362f33332f30362f31312f666f726b6d6531322e706e67) at the top of this page.
 3. Clone the fork to your computer using: `git clone https://github.com/YOUR_USERNAME/boats-animator.git` or [GitHub Desktop](https://desktop.github.com/).
 4. Run `npm install` in the `boats-animator` directory.
 
 ### Running from source code
-To preview Boats Animator simply run `npm start` in a terminal window. Note: the first time this is run a copy of NW.js will be downloaded, this is around 50MB.
 
-### Compiling from source code
-* To build Linux, Mac and Windows executable files for Boats Animator run: `npm run-script build`.
-* To customise which builds are output further run: `node build --help`.
+To preview Boats Animator simply run `npm start` in a terminal window.
+
+### Building from source code
+
+To build packages for Boats Animator for the current operating system run: `npm run-script build`.
 
 ## Reporting issues
+
 If you find a bug or want to suggest an improvement:
+
 * First check someone else hasn't already reported it in the [issues](https://github.com/charlielee/boats-animator/issues) section.
 * If not, create a [new issue](https://github.com/charlielee/boats-animator/issues/new) for it.
 * Please make sure to include a clear **title** and **description** as well as any relevant error messages, code snippets or screenshots.
 
 ## Submitting changes
+
 If you're working on an improvement to Boats Animator it is usually good practise to add a comment to the [relevant issue](https://github.com/charlielee/boats-animator/issues). Once you are ready to submit your changes you should:
+
 * Create a [new pull request](https://github.com/charlielee/boats-animator/pull/new/master) with a clear list of what you've done *([read more about pull requests](http://help.github.com/pull-requests/))*.
 * The pull request should reference any relevant issues and have a clear title.
 * The log messages for any commits should also be clear.
 * The coding conventions for Boats Animator should be followed.
 * If your pull request brings any visible changes, the Markdown based documentation in the `docs` directory should be updated.
 
 ## Coding conventions
+
 The following conventions should be observed in Boats Animator's code:
-* HTML5, CSS3 and ES6 JavaScript that is supported by Chromium 71 may be used.
+
 * Features with the `Webkit` prefix may be used if there is no standardised method available.
 * Code should use **2 space indentation**.
 * Trailing white space should be avoided.