title: Dynamically add cells to SwiftUI LazyGrid
body: <p>How to dynamically add cells (not columns) to some LazyVGrid in SwiftUI?
  The following code should add 1 cell by clicking the button. It compiles but doesn't work.
  What I a missing?</p>
  <pre><code>import SwiftUI
  
  struct GridContent: Identifiable {
      var id = UUID()
  }
  
  struct ContentView: View {
  
      @State var counter = [ GridContent() ]
      var gridLayout = [ GridItem() ]
         
      var body: some View {
          LazyVGrid(columns: gridLayout) {
              ForEach(counter.indices) { item in
                  Text(&quot;\(item)&quot;)
              }
              Button(action: {
                  counter.append(GridContent())
              }) {
                  Image(systemName: &quot;plus.circle.fill&quot;)
              }
          }
      }
  }
  </code></pre>