title: git ignore specific changes in file but not all the file
body: <p>how to ignore some changes in a file but not all the file</p>
  <p>example:
  I want git to ignore the changes in a file if the only changes are like</p>
  <pre><code>Generation Time: 2022-02-21 16:42:18
  </code></pre>
  <p>if it's the only difference, I want git to skip it as changed</p>