Merge branch 'nickcolley-add-link-to-update-slack-themes'

source/layouts/layout.erb

@@ -360,7 +360,10 @@
                         <span class="input_note">Mention Badge</span>
                     </div> -->
 
-                    <p class="input_note no_bottom_margin">Copy and paste these values to your <strong>Slack</strong> settings <strong>Sidebar Theme</strong> section:</p>
+                    <p class="input_note no_bottom_margin">
+                        Copy and paste these values to your <strong>Slack</strong> settings
+                        <a target="_blank" href="https://get.slack.help/hc/en-us/articles/205166337-Customizing-your-Slack-theme"><strong>Sidebar Theme</strong></a> section:
+                    </p>
                     <input type="text" name="sidebar_theme_custom" id="sidebar_theme_custom" class="monospace subtle_silver no_top_margin" ng-model="colors">
                 </div>
             </div>