Restyle sign-in page. Mention public projects

app/assets/stylesheets/sections/login.scss

 /* Login Page */
 body.login-page{
-  background: #474D57;
-  .container .content { padding-top: 4%; }
+  .container > .content {
+    padding-top: 20px;
+  }
 }
 
 .login-box{

app/views/layouts/devise.html.haml

@@ -6,5 +6,10 @@
     .container
       .content
         %center
-          = image_tag image_path "login-logo.png"
+          %h1 GitLab
+          %p.light
+            GitLab is open source software to collaborate on code.
+            %br
+            #{link_to "Sign in", new_user_session_path} or browse for #{link_to "public projects", public_projects_path}.
+        %hr
         = yield