Added/removed blank lines in the docs for consitency

docs/migration.html

@@ -6,7 +6,6 @@ lead: "Guidance on how to upgrade from Bootstrap v2.x to v3.x with emphasis on m
 ---
 
 
-
 <!-- Migration
 ================================================== -->
 <div class="bs-docs-section">
@@ -316,7 +315,6 @@ lead: "Guidance on how to upgrade from Bootstrap v2.x to v3.x with emphasis on m
     </table>
   </div><!-- /.table-responsive -->
 
-
   <h2 id="dropped">What's removed</h2>
   <p>The following elements have been dropped or changed in v3.0.</p>
   <div class="table-responsive">
@@ -423,7 +421,6 @@ lead: "Guidance on how to upgrade from Bootstrap v2.x to v3.x with emphasis on m
     </table>
   </div><!-- /.table-responsive -->
 
-
   <h2 id="notes">Additional notes</h2>
   <p>Other changes in v3.0 are not immediately apparent. Base classes, key styles, and behaviors have been adjusted for flexibility and our <em>mobile first</em> approach. Here's a partial list:</p>
   <ul>