Update pull request naming convention in exercise

Author: MakisH

03_building_and_packaging/cmake_exercise.md

@@ -8,7 +8,7 @@ Deadline: **Wednesday, November 26th, 2025, 9:00**
 
 ## Overview
 
-- The goal of the exercise is to open a pull request from a fork of [the CMake exercise repository](https://github.com/Simulation-Software-Engineering/cmake-exercise). Please name your pull request `Add building and container recipes`.
+- The goal of the exercise is to open a pull request from a fork of [the CMake exercise repository](https://github.com/Simulation-Software-Engineering/cmake-exercise). Please name your pull request `[username] Add building and container recipes`.
 - Your pull request should add a `Dockerfile` and a `CMakeLists.txt`, besides some minor changes in `main.cpp`, such as commenting in some code parts.
 - From your pull request, it should be possible to create an executable container. After running the container, it should be possible to `cd` into `cmake-exercise` and then run the `build_and_run.sh` script.
 - Use as many of the currently commented-out additional files, which induce additional dependencies.