title: Does an editor with a "multiple versions in a single file" feature exist?
body: <p>I'm new to the programming community in general and I'm not sure how I would search for this but, does such an an editor with a feature that allows to save different versions of a code in a single file exist? If yes, what do you call the feature?</p>
  
  <p>Basically I want to look through an entire code file and be able to identify (through highlights? or code folding?) which code snippets has been edited or added in which version. Either that, or be able to switch through each version of the file (listed in order). </p>
  
  <p>This is so I can save and document each code snippet I add or edit, step-by-step, so I can look back at it and easily understand the logic of how I created the code.</p>