Unconditionally include Debuggability section in generated emails (#1409)

Issue: #1372

templates/blink/intent_to_implement.html

@@ -150,10 +150,8 @@
 
 {% endif %}
 
-{% if feature.debuggability %}
-  <br><br><h4>Debuggability</h4>
-  <p class="preformatted">{{feature.debuggability|urlize}}</p>
-{% endif %}
+<br><br><h4>Debuggability</h4>
+<p class="preformatted">{{feature.debuggability|urlize}}</p>
 
 {% if 'experiment' in sections_to_show %}
   <br><br><h4>Will this feature be supported on all six Blink platforms