Make welcome screen prettier

// FREEBIE

background.html

@@ -33,6 +33,7 @@
     </div>
     <div class='conversation-stack'>
       <div class='conversation placeholder'>
+        <img src='/images/icon_128.png' />
         <h3>{{ welcomeToSignal }}</h3>
         <p>{{ selectAContact }}</p>
       </div>

stylesheets/_index.scss

@@ -225,7 +225,10 @@ input.search {
 .conversation.placeholder {
   text-align: center;
   padding: 100px 36px;
-  color: #aaa;
+
+  h3 {
+    font-size: large;
+  }
 }
 .contact.placeholder {
   position: absolute;

stylesheets/manifest.css

@@ -709,8 +709,9 @@ input.search {
 
 .conversation.placeholder {
   text-align: center;
-  padding: 100px 36px;
-  color: #aaa; }
+  padding: 100px 36px; }
+  .conversation.placeholder h3 {
+    font-size: large; }
 
 .contact.placeholder {
   position: absolute;