Add CodePen template

<https://codepen.io/pen?template=YeEWom>

Author: samme

.github/CONTRIBUTING.md

@@ -14,7 +14,7 @@ Before contributing, please read the [code of conduct](https://github.com/photon
 
 **3. Create an isolated and reproducible test case.** If you are reporting a bug, make sure you also have a minimal, runnable, code example that reproduces the problem you have.
 
-**4. Include a live example.** After narrowing your code down to only the problem areas, make use of [jsFiddle][1], [jsBin][2], or a link to your live site so that we can view a live example of the problem.
+**4. Include a live example.** After narrowing your code down to only the problem areas, make use of [jsFiddle][1], [jsBin][2], [CodePen][5], or a link to your live site so that we can view a live example of the problem.
 
 **5. Share as much information as possible.** Include browser version affected, your OS, version of the library, steps to reproduce, etc. "X isn't working!!!1!" will probably just be closed.
 
@@ -74,3 +74,4 @@ Thanks to Chad for creating the original Pixi.js Contributing file which we adap
 [2]: http://jsbin.com/
 [3]: http://nodejs.org
 [4]: http://www.html5gamedevs.com/forum/14-phaser/
+[5]: https://codepen.io/pen?template=YeEWom "Phaser 3 game template"

.github/ISSUE_TEMPLATE.md

@@ -10,7 +10,7 @@ This Issue is about (delete as applicable)
 * An error on the web site
 * A problem with my own code
 
-API errors must include example code showing what happens, and why you don't believe this is the expected behavior. Issues posted without code take _far_ longer to get resolved, _if ever_. Feel free to use a site such as jsbin to demo the problem. If we can run it, and see the error, we can usually fix it.
+API errors must include example code showing what happens, and why you don't believe this is the expected behavior. Issues posted without code take _far_ longer to get resolved, _if ever_. Feel free to use a site such as jsBin or [CodePen](https://codepen.io/pen?template=YeEWom) to demo the problem. If we can run it, and see the error, we can usually fix it.
 
 If your Issue contains _any_ form of hostility it will be instantly closed.