title: Can one add further source files to an executable once defined?
body: <p>Given I have defined an executable with its main source file in a <code>CMakeList.txt</code> file:</p>
  
  <pre><code>ADD_EXECUTABLE(MyExampleApp main.cpp)
  </code></pre>
  
  <p>Can I add further source files to this executable after this line but in the same or an included <code>CMakeList.txt</code> file?</p>