Add missing quotation marks

fixes #253

index.html

@@ -895,7 +895,7 @@
 <a href="https://requestpolicycontinued.github.io/">https://requestpolicycontinued.github.io/</a>
 </p>
 -->
-		<h3>Stop cross-site requests with uMatrix</h3>
+		<h3>Stop cross-site requests with "uMatrix"</h3>
 		<img src="img/addons/uMatrix.gif" class="img-responsive pull-left" alt="uMatrix" style="margin-right:30px;">
 		<p>Many websites integrate features which let other websites track you, such as Facebook Like Buttons or Google Analytics. uMatrix gives you control over the requests that websites make to other websites. This gives you greater and more fine grained control
 			over the information that you leak online.