update header and subscribe

Author: jessesquires

_includes/header.html

@@ -7,6 +7,7 @@ <h1><a href="/">{{ site.title }}</a></h1>
          <div class="tagline col-sm-8 col-sm-offset-2 col-md-8 col-md-offset-2">
             <h2>A community-driven weekly newsletter about <a href="https://swift.org/" target="_blank">Swift.org</a>.
             Curated by <a href="{{ site.author.url }}" target="_blank">{{ site.author.name }}</a> and published for free every Thursday.
+            <a href="/subscribe">Subscribe</a> to get the best summary about what's happening in the Swift open source project every week.
             </h2>
          </div> <!-- col -->
       </div> <!-- col -->

subscribe.html

@@ -5,8 +5,8 @@
 
 <div class="row">
    <div class="col-sm-8 col-sm-offset-2 col-md-8 col-md-offset-2">
-      <h2 class="text-center">Subscribe to our mailing list!</h2>
-      <p class="text-center text-muted"><small>No spam. We'll never share your email address and you can opt out at any time.</small></p>
+      <h2 class="text">Subscribe to our mailing list!</h2>
+      <p class="lead">Get the best summary about what's happening in the Swift open source project every week.</p>
 
       <!-- Begin MailChimp Signup Form -->
       <div id="mc_embed_signup">
@@ -60,6 +60,7 @@ <h2 class="text-center">Subscribe to our mailing list!</h2>
                   <button type="submit" name="subscribe" class="btn btn-warning btn-lg btn-block">Subscribe</button>
                   <!-- id="mc-embedded-subscribe" -->
                </div>
+               <p class="text-center text-muted"><small>No spam. We'll never share your email address and you can opt out at any time.</small></p>
          </form>
       </div> <!-- mc_embed_signup -->
    </div> <!-- col -->