Update CONTRIBUTING.md

CONTRIBUTING.md

@@ -1,5 +1,8 @@
 ## How to contribute to IRI
 
+#### **How should a Pull Request look like**?
+Before creating a PR make sure you have read the entire contributing guideline. Ensure the PR description clearly describes the problem and solution by following the template. It is best to discuss your changes in an issue before creating the PR. A PR should address a **specific concern**. If it addresses more than one concern it **should be split**. Small PRs get merged in faster. Very large PRs are difficult to review and test. This makes them less likely to be merged.
+
 #### **Did you find a bug?**
 
 * **Do not open a GitHub issue if the bug is a security vulnerability
@@ -13,8 +16,6 @@
 
 * [New issues](https://github.com/iotaledger/iri/issues/new) should be used for reporting issues. If you already wrote a patch for an issue that you or someone else reported, make sure you link it to the open issue. You can do this by mentioning the issue number in the comment or description on the PR, for example `#123` to link issue "123". 
 
-* Ensure the PR description clearly describes the problem and solution. Very large PRs are difficult to review and test. This makes them less likely to be merged. If possible, split the PR into multiple PRs, each addressing a specific concern or scenario. Only make the code changes necessary to address the actual issue.
-
 #### **Do you intend to add a new feature or change an existing one?**
 
 * Suggest your change as a [new issues](https://github.com/iotaledger/iri/issues/new). Use the second part of the issue template, dedicated to new feature requests and delete the first part. If you plan on implementing the change yourself, start writing the code and submit a PR. Note that the fact that the feature is "code ready" doesn't mean it will get merged. It is advisable to gather feedback for the change first. You are encouraged to start and drive a discussion on [Discord](https://discordapp.com/invite/fNGZXvh). The IRI team also monitors the repo and will provide feedback where relevant. 
@@ -32,4 +33,4 @@ Thanks! :heart: :heart: :heart:
 
 The contribution guidelines are inspired by the Ruby on Rails contribution guidelines. 
 
-IRI Team
+IRI Team