Add option to reposition the expand thread button (CC)

This option repositions the expand thread button all the way to the left
of the thread element in thread lists (Community Console). Originally,
this button is shown in the right.

Requested at pekb/thread/67965396?msgid=91547227.

Change-Id: I10cd62998f6165ec58705fd912089119a7e0a108
diff --git a/src/options/options.html b/src/options/options.html
index 62fce67..69cddd8 100644
--- a/src/options/options.html
+++ b/src/options/options.html
@@ -34,6 +34,7 @@
       <div class="option"><input type="checkbox" id="batchlock"> <label for="batchlock" data-i18n="batchlock"></label> <span class="experimental-label" data-i18n="experimental_label"></span></div>
       <div class="option"><input type="checkbox" id="smei_sortdirection"> <label for="smei_sortdirection" data-i18n="smei_sortdirection"></label> <span class="experimental-label" data-i18n="experimental_label"></span></div>
       <div class="option"><input type="checkbox" id="enhancedannouncementsdot"> <label for="enhancedannouncementsdot" data-i18n="enhancedannouncementsdot"></label></div>
+      <div class="option"><input type="checkbox" id="repositionexpandthread"> <label for="repositionexpandthread" data-i18n="repositionexpandthread"></label> <span class="experimental-label" data-i18n="experimental_label"></span></div>
       <h4 data-i18n="profileindicator_header"></h4>
       <div class="option"><input type="checkbox" id="profileindicator"> <label for="profileindicator" data-i18n="profileindicator"></label> <span class="experimental-label" data-i18n="experimental_label"></span></div>
       <div class="option"><input type="checkbox" id="profileindicatoralt"> <label for="profileindicatoralt" data-i18n="profileindicatoralt"></label> <span class="experimental-label" data-i18n="experimental_label"></span></div>