Add Simple Documentation

lib/service/configuration_service.dart

@@ -6,6 +6,12 @@ class ConfigurationService {
   bool showGrid;
 
   int _simSpeed;
+
+  /// Simulation Speed
+  ///
+  /// Sets the number of updates the simulation takes per second. Can range from
+  /// 1 to arbitrarily high numbers (though setting it too high can potentially
+  /// make the app brittle).
   int get simSpeed => _simSpeed;
   void set simSpeed(int val) {
     _simSpeed = val;