Add entry about gray checkmarks

faq.html

@@ -70,11 +70,19 @@
       or not. To disable the vibration, open your phone's settings, tap "Sounds"
       and disable &quot;Vibrate on touch&quot;.</p>
       
+      <h4>Why are some checkmarks gray?</h4>
+      
+      <p>The color gray indicates that the checkmark was automatically added by the
+      app, and not manually by the user. This happens with non-daily habits. For
+      example, if you have a habit that should be repeated only one time every week,
+      and you perform it on a certain Monday, the app will automatically add gray
+      checkmarks on Tuesday, Wednesday an so on.</p>
+      
       <h3>Importing and exporting data</h3>
       
       <h4>If I uninstall the app, will I lose all my data?</h4>
       
-      <p><strong>Yes, uninstalling the app will delete all your data!</strong> All files inside the
+      <p>Yes, uninstalling the app will delete all your data! All files inside the
       folder <code>Android » data » org.isoron.uhabits</code> on the SD card will also be deleted.
       This is the way Android was designed, and there is nothing Loop can do to
       prevent it.</p>
@@ -212,7 +220,7 @@
       <a href='http://sass-lang.com/'>sass</a>
       <br>
       Last update:
-      2016-04-03
+      2016-04-04
     </div>
   </body>
 </html>