macos: add settings view with a coming soon to help some people

macos/Sources/SettingsView.swift

@@ -0,0 +1,28 @@
+import SwiftUI
+
+struct SettingsView: View {
+    var body: some View {
+        HStack {
+            Image("AppIconImage")
+                .resizable()
+                .scaledToFit()
+                .frame(width: 128, height: 128)
+            
+            VStack(alignment: .leading) {
+                Text("Coming Soon. 🚧").font(.title)
+                Text("You can't configure settings in the GUI yet. To modify settings, " +
+                     "edit the file at $HOME/.config/ghostty/config and restart Ghostty.")
+                .multilineTextAlignment(.leading)
+                .lineLimit(nil)
+            }
+        }
+        .padding()
+        .frame(minWidth: 500, maxWidth: 500, minHeight: 156, maxHeight: 156)
+    }
+}
+
+struct SettingsView_Previews: PreviewProvider {
+    static var previews: some View {
+        SettingsView()
+    }
+}