title: Delete a nested array from firestore
body: <p>i have a nested array (arrays inside an array) of frame numbers in which each frame number has its own data.
  I am not bothered about the frame number right now.</p>
  <p>considering the array as <code>[[0-100][100-200][200-300][300-400][400-500]]</code> where <code>[0-100] [100-200]</code> is an array of frame numbers. If i want to delete the <code>[100-200]</code> array, what should I do?</p>