docs(guide/$location): fix table header formatting

Closes angular#13456

Author: gkalpak

docs/app/assets/css/docs.css

@@ -641,6 +641,12 @@ ul.events > li {
   vertical-align: top;
 }
 
+.table > tbody > tr.head > td,
+.table > tbody > tr.head > th {
+  border-bottom: 2px solid #ddd;
+  padding-top: 50px;
+}
+
 @media only screen and (min-width: 769px) and (max-width: 991px) {
   .main-body-grid {
     margin-top: 160px;

docs/content/guide/$location.ngdoc

@@ -771,8 +771,8 @@ then uses the information it obtains to compose hashbang URLs (such as
     </tr>
 
     <tr class="head">
-      <td>Navigation outside the app</td>
-      <td>Use lower level API</td>
+      <th>Navigation outside the app</td>
+      <th>Use lower level API</td>
     </tr>
 
     <tr>
@@ -786,8 +786,8 @@ then uses the information it obtains to compose hashbang URLs (such as
     </tr>
 
     <tr class="head">
-      <td>Read access</td>
-      <td>Change to</td>
+      <th>Read access</td>
+      <th>Change to</td>
     </tr>
 
     <tr>