title: How to update a cell's content when its referenced cells content changes
body: <p>I looked through 'similar' questions but couldn't find a solution to my problem.  Basically I'm learning about events and notifiers and my problem is, how do I update a reference to a cell when the referenced cell's content changes.  For example: What I currently can do is reference another cells content.
  If I have something like this</p>
  
  <p><a href="https://i.stack.imgur.com/mM0LY.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/mM0LY.png" alt="Initial reference"></a></p>
  
  <p>I get this</p>
  
  <p><a href="https://i.stack.imgur.com/1oDC6.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/1oDC6.png" alt="Reference is good"></a></p>
  
  <p>But if I update A1's cell to something else, how can I get C1 cell to update?
  Any help would be greatly appreciated.</p>
  
  <p><a href="https://i.stack.imgur.com/ct6FT.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ct6FT.png" alt="problem"></a></p>