Launch threadListAvatars feature

This CL adds the docs for the feature and promotes the feature from an
experiment to an option.

Fixed: twpowertools:28, twpowertools:26
Change-Id: I69d6eccc5fe83c802718e255fa9967f804f3d9a6
diff --git a/src/common/optionsPrototype.json5 b/src/common/optionsPrototype.json5
index a5caa3e..80020ce 100644
--- a/src/common/optionsPrototype.json5
+++ b/src/common/optionsPrototype.json5
@@ -95,13 +95,13 @@
     context: 'options',
     killSwitchType: 'option',
   },
-
-  // Experiments:
   'threadlistavatars': {
     defaultValue: false,
-    context: 'experiments',
-    killSwitchType: 'experiment',
+    context: 'options',
+    killSwitchType: 'option',
   },
+
+  // Experiments:
   'autorefreshlist': {
     defaultValue: false,
     context: 'experiments',
diff --git a/src/options/optionsPage.json5 b/src/options/optionsPage.json5
index 694c7dc..9647dd6 100644
--- a/src/options/optionsPage.json5
+++ b/src/options/optionsPage.json5
@@ -26,6 +26,7 @@
         {codename: 'batchlock'},
         {codename: 'enhancedannouncementsdot'},
         {codename: 'repositionexpandthread', experimental: true},
+        {codename: 'threadlistavatars'},
       ],
     },
     {
diff --git a/src/static/options/experiments.html b/src/static/options/experiments.html
index 81c8a10..b835e17 100644
--- a/src/static/options/experiments.html
+++ b/src/static/options/experiments.html
@@ -12,7 +12,6 @@
       <h1 data-i18n="experiments_title"></h1>
       <p data-i18n="experiments_description"></p>
       <form>
-        <div class="option"><input type="checkbox" id="threadlistavatars"> <label for="threadlistavatars" data-i18n="threadlistavatars"></label></div>
         <div class="option"><input type="checkbox" id="autorefreshlist"> <label for="autorefreshlist" data-i18n="autorefreshlist"></label></div>
         <div class="actions"><button id="save" data-i18n="save"></button></div>
       </form>