Explain how to check the versions of node and mongo for people who already have these installed on their machine. This helps prevent contributors from using older versions that may be incompatible.

Remove inconsistent tabbing and give directions in case versions are not up to date

Removing extra line

CONTRIBUTING.md

@@ -41,6 +41,15 @@ Remember to feel free to ask for help in our [Contributors](https://gitter.im/Fr
 
 > _Updating to the latest releases is recommended_.
 
+If Node or MongoDB is already installed in your machine, run the following commands to validate the versions:
+
+```shell 
+node -v 
+mongo --version
+``` 
+
+If your versions are lower than the prerequisite versions, you should update. 
+
 ### Forking The Project
 
 #### Setting Up Your System