Minor fixes to extensions docs

Related to space-ros#18

docs/extensions/index.md

@@ -2,5 +2,5 @@
 
 Extensions are a way to add new functionality to the core of the application. They can be used to add new features, modify existing ones, or even remove them. Extensions are a powerful way to customize the application to your needs. The extension module of Space ROS has a collection of extensions that can be used to add new features to the application. The extensions that are available in the extension module are:
 
- - [Rover Simle Controller](./rover-simle-controller.md) - This extension adds a simple controller for the rover in the simulation environment to allow controlling mobile platforms using teleoperation.
- - [Omnigraph Example](./omnigraph-example.md) - This extension provides an example of how to use the omnigraph node feature in the application to create custom graphs for the simulation environment.
+ - [Rover Simple Controller](./rover-simle-controller.md) - This extension adds a simple controller for the rover in the simulation environment to allow controlling mobile platforms using teleoperation.
+ - [Omnigraph Example](./negate-number.md) - This extension provides an example of how to use the omnigraph node feature in the application to create custom graphs for the simulation environment.