Allow enable all documentations feature

assets/javascripts/app/router.coffee

@@ -92,6 +92,13 @@ class app.Router
   settings: (context) ->
     return "/#/#{context.path}" if app.isSingleDoc()
     @triggerRoute 'settings'
+
+    # Allows check all the checkboxes in /settings.
+    # This event needs to be added runtime since the button is
+    # added to the sidebar when the page is loaded, not like
+    # other elements that are hidden and are shown when the page
+    # loads
+    app.document.settings.setCheckboxesEvent()
     return
 
   offline: (context)->

assets/javascripts/templates/sidebar_tmpl.coffee

@@ -60,7 +60,10 @@ templates.sidebarDisabledList = (html) ->
 templates.sidebarDisabledVersionedDoc = (doc, versions) ->
   """<a class="_list-item _list-dir _icon-#{doc.icon} _list-disabled" data-slug="#{doc.slug_without_version}" tabindex="-1">#{arrow}#{doc.name}</a><div class="_list _list-sub">#{versions}</div>"""
 
-templates.docPickerHeader = """<div class="_list-picker-head"><span>Documentation</span> <span>Enable</span></div>"""
+templates.docPickerHeader = """
+<div class="_list-picker-head"><span>Documentation</span> <span>Enable</span></div>
+<div class="_list-picker-head _centered-list-picker-head" id="enable-all"><div>Enable all</div></div>
+"""
 
 templates.docPickerNote = """
   <div class="_list-note">Tip: for faster and better search results, select only the docs you need.</div>

assets/javascripts/views/layout/settings.coffee

@@ -81,3 +81,19 @@ class app.views.Settings extends app.View
       $.stopEvent(event)
       app.router.show '/'
     return
+
+  setCheckboxesEvent: =>
+    button = document.getElementById('enable-all')
+    button.addEventListener 'click', @checkAllCheckboxes
+    return
+
+  checkAllCheckboxes: =>
+    checkboxes = document.getElementsByClassName('_list-checkbox')
+    i = 0
+
+    while (i < checkboxes.length)
+      checkboxes[i].checked = true
+      i++
+
+    @addClass('_dirty')
+    return

assets/stylesheets/components/_sidebar.scss

@@ -367,3 +367,20 @@
   &:after { visibility: hidden; }
   &:hover:after { visibility: visible; }
 }
+
+._centered-list-picker-head {
+    cursor: pointer;
+    text-aling: center;
+    color: var(--textColor);
+    @extend %border-box;
+
+    & div{
+        margin-left: auto;
+        margin-right: auto;
+    }
+
+    &:active {
+        box-shadow: inset 0 1px 1px rgba(black, .05), inset 0 1px 4px var(--boxBorder);
+    }
+
+}