message: Add bug reports to CONTRIBUTING
diff: Thank you for considering contributing to Embla Carousel, contributions are welcome!
  -- [Code Style](#code-style)
  -- [New Features](#new-features)
  +- [Code style](#code-style)
  +- [New features](#new-features)
  +- [Bug reports](#bug-reports)
  ### Code style
  +
  All code contributions should follow the current `code style`. Embla Carousel is written with `function factories` that expose an object containing a set of public methods. Note that the public method object should be flat and frozen. Below is an example:
  ```typescript
  @@ -25,21 +27,31 @@ export function FunctionFactory(params: Params): FunctionFactory {
  const privateVariable = 10
  function publicMethod() {
  - return parameter + privateVariable;
  + return parameter + privateVariable
  }
  const self: FunctionFactory = {
  - publicMethod
  + publicMethod,
  }
  return Object.freeze(self)
  }
  ```
  ### New features
  +
  For any new features it's important to follow this checklist:
  +
  - **`Discuss:`** Open an issue before starting any significant work. Let's discuss to see how the proposed feature fits within Embla Carousels's vision.
  - **`Prettier:`** Make sure your editor adheres to prettier configuration files.
  - **`Code style:`** Follow the current code style as described [here](#code-style).
  - **`Create a Pull Request:`** Make sure your branch name follows this pattern `feature/branchname-goes-here`.
  +### Bug reports
  +
  +All bug reports require a reduced test case. Providing a test case is the best way to get any issue addressed. It helps us all to understand the problem. Without this, your issue **may be closed**. Please follow this checklist:
  +
  +- **`Test case:`** Create one by forking the following [CodeSandbox](https://codesandbox.io/s/embla-carousel-loop-false-oyols).
  +- **`Demonstrate:`** Make sure the test case clearly demonstrates the issue.
  +- **`Do not:`** Provide a link to a production site. That's not a test case.
  +
  Your code will be used as part of an open source product if merged. By submitting a Pull Request, **you are giving your consent** for your code to be integrated into Embla Carousel as part of an open source product.
  