Move documentation to Gitbook (#206)

.editorconfig

@@ -4,6 +4,8 @@
 root = true
 
 [*.md]
+indent_style = space
+indent_size = 4
 charset = utf-8
 end_of_line = lf
 

CONTRIBUTING.md

@@ -6,20 +6,23 @@ We accept contributions via Pull Requests on [Github](https://github.com/10up/wp
 
 ## Branches
 
-* We try to follow [SemVer](http://semver.org/) in WP Mock
+* WP_Mock adheres to [SemVer](http://semver.org/) (semantic versioning).
 * The current "stable" release version lives on the **trunk** branch.
 * If there is a current development release, it will live on a **{version}-dev** branch.
 
 ## Pull Requests
 
-* New features must be submitted against the **trunk** branch
+* New features must be submitted against the **trunk** branch.
 * Bug fixes should be submitted against the branch in which the bug exists, which is likely **trunk**.
 * If you're not sure whether a feature idea would be something we'd be interested in, please open an issue before you start working on it. We'd be happy to discuss your idea with you.
+* Please update the **documentation** as appropriate to reflect any changes or features you have introduced in your pull request.
+* Please implement appropriate **unit tests** for any code changes you are submitting in your pull request.
 
 ## Merging
 
 * As of 2019, all merges to the **trunk** branch will be squash merges of features.
 * If there are multiple features pending in a release, we will create a **{version}-dev** branch to track development against that version. Once the version is ready, that branch will be squash-merged into **trunk** as well.
+* When a pull request is merged, the **Squash and Merge** option **must be used** when merging a pull request.
 
 ## Thanks