Merge pull request #504 from guidokessels/readme-update

Update README for AMG and better PRs

README.md

@@ -1,6 +1,6 @@
 # X-Wing Data 2
 
-An easy-to-use collection of all data from [X-Wing: The Miniatures Game (Second Edition)](https://www.fantasyflightgames.com/en/products/x-wing-second-edition/) by [Fantasy Flight Games](http://fantasyflightgames.com/).
+An easy-to-use collection of all data from [X-Wing: The Miniatures Game (Second Edition)](https://www.atomicmassgames.com/xwing-documents) by [Atomic Mass Games](https://www.atomicmassgames.com/).
 
 If you're looking for data and images of X-Wing First Edition, you can find that here: [xwing-data](https://github.com/guidokessels/xwing-data).
 
@@ -50,6 +50,15 @@ You can run these scripts using `npm` or `yarn`. For example:
 | `yarn run validate:tests`       | Run all unit tests                                                                                                                                          |
 | `yarn run validate:tests:watch` | Run all unit tests in watch mode                                                                                                                            |
 
+## Creating a pull request
+
+Before opening a pull request, see the following checklist:
+
+1. Use sensible commit messages. Good: `add rebel fangs`. Bad: `create fang-fighter.json`
+1. Ensure there are no merge conflicts with `master` (rebase on top of `master` or merge it into your branch)
+1. Ensure tests pass: `yarn run validate:tests`
+1. Use a sensible PR message, eg `add pride of mandalore rebel content`. PR messages can be the same as commit messages for single-commit PRs.
+
 ## Creating a release
 
 Go through these steps to create a new release: