Add more README touchups

Author: ivov

README.md

@@ -47,15 +47,15 @@ Sign in using a Google or Facebook account, e-mail/password or anonymously. In a
 
 <p align="center">
     <img src="demo/sign_in.png" height="500px">
+    &nbsp;&nbsp;&nbsp;&nbsp;
+    <img src="demo/sign_in_email.png" height="500px">
 </p>
 
 <p align="center">
     <img src="demo/sign_in_google.png" height="500px">
     &nbsp;&nbsp;&nbsp;&nbsp;
     <img src="demo/sign_in_facebook.png" height="500px">
     &nbsp;&nbsp;&nbsp;&nbsp;
-    <img src="demo/sign_in_email.png" height="500px">
-    &nbsp;&nbsp;&nbsp;&nbsp;
 </p>
 
 Based on Firestore's auth stream, the app redirects a signed-in user to the home screen and a signed-out user to the sign-in page. Signed-in status is preserved.

demo/article_favoriting.gif

@@ -10,7 +10,6 @@ import 'package:infobootleg/models/search_state_model.dart';
 import 'package:infobootleg/utils/hex_color.dart';
 import 'package:infobootleg/models/law_model.dart';
 import 'package:infobootleg/widgets/alert_box.dart';
-import 'package:infobootleg/utils/exceptions.dart';
 
 enum ModificationType { modifies, isModifiedBy }
 
@@ -121,7 +120,7 @@ class LawSummaryScreen extends StatelessWidget {
       final bool answer = await AlertBox(
         title: "Formato desconocido",
         content:
-            "La Ley ${searchState.activeLaw.number} tiene formato desconocido y la aplicación no puede procesarla.\n¿Abrir esta ley en InfoLeg en el navagador?",
+            "La Ley ${searchState.activeLaw.number} tiene formato desconocido y la aplicación no puede procesarla.\n\n¿Abrir esta ley en InfoLeg en el navagador?",
         confirmActionText: "Sí",
         cancelActionText: "No",
       ).show(context);