Fix #30

Author: mmmarinho

docs/source/gazebo/installation.rst

@@ -49,7 +49,7 @@ Running :program:`Gazebo`
 
     Content from ``ROS 2 Networking and Communication``
 
-        https://github.com/UoMMScRobotics/UOMDocumentationForLeoRover/blob/main/Further_reading/Networking.m
+        https://github.com/UoMMScRobotics/UOMDocumentationForLeoRover/blob/main/Further_reading/Networking.md
         by https://github.com/Https404PaigeNotFound
 
 After installation, :program:`Gazebo Harmonic` can be run with the following command
@@ -70,4 +70,4 @@ Which should result in something similar to the following, if the installation w
 
 .. _curl: https://curl.se/
 .. _lsb-release: https://packages.debian.org/sid/lsb-release
-.. _gnupg: https://gnupg.org/download/
+.. _gnupg: https://gnupg.org/download/