Update README.md

Added more specific references to the development environment setup guide and the development contribution guidelines

Author: MateStrysewske

README.md

@@ -17,7 +17,7 @@
 You can give SORMAS a try on our play server at https://sormas.helmholtz-hzi.de!
 
 #### How Can I Get Involved?
-Have a look at our [*Contributing Readme*](CONTRIBUTING.md) and contact us at [email protected] or join our [developer chat on Gitter](https://gitter.im/SORMAS-Project) to learn how you can help to drive the development of SORMAS forward and to get development support from our core developers. SORMAS is a community-driven project, and we'd love to have you on board!
+Read through our [*Contributing Readme*](CONTRIBUTING.md) and contact us at [email protected] or join our [developer chat on Gitter](https://gitter.im/SORMAS-Project) to learn how you can help to drive the development of SORMAS forward and to get development support from our core developers. SORMAS is a community-driven project, and we'd love to have you on board! If you want to contribute to the code, please strictly adhere to the [*Development Environment*](DEVELOPMENT_ENVIRONMENT.md) guide to ensure that everything is set up correctly. Please also make sure that you've read the [*Development Contributing Guidelines*](CONTRIBUTING.md#development-contributing-guidelines) before you start to develop.
 
 #### How Can I Report a Bug or Request a Feature?
 Please [create a new issue](https://github.com/hzi-braunschweig/SORMAS-Project/issues/new/choose) and read the [*Submitting an Issue*](CONTRIBUTING.md#submitting-an-issue) guide for more detailed instructions. We appreciate your help!