[meta] Update CONTRIBUTING.md

CONTRIBUTING.md

@@ -1,23 +1,23 @@
-## How to contribute
+# Contributing
 
-### Creating an issue
+## Creating an issue
 Remember to include enough information if you're reporting a bug.  
 Creating an issue to ask a question is fine.
 
-### Creating a PR
+## Creating a PR
 Every PR will be considered.
 
-#### How to increase the chance of having your PR merged
+### How to increase the chance of having your PR merged
 
 * Ask about the feature beforehand (or pick one of the open issues)
 * If no issue exists, create an issue for the PR
 * Try to write some tests for your change. There are a lot of examples in the `test` dir.
 * Format your code so it looks somewhat like the rest of the source (which is formatted using default settings in IntelliJ)
 
-### How to run tests
+## Runnning tests
 
 `mvn test`
 
-### How to install in local Maven repository for development testing
+## Building project locally
 
 `mvn install`