Add missing period to homepage text (#150)

Author: phoqe

src/app/pages/homepage/homepage.html

@@ -18,7 +18,7 @@ <h2> Material Design components for Angular apps</h2>
     <div class="docs-homepage-promo-desc">
       <h2>Sprint from Zero to App</h2>
       <p>Hit the ground running with comprehensive, modern UI components that work across
-        the web, mobile and desktop</p>
+        the web, mobile and desktop.</p>
     </div>
   </div>
   <div class="docs-homepage-row docs-homepage-reverse-row">