use translations (doh)

app/assets/javascripts/discourse/templates/modal/reorder-categories.hbs

@@ -2,8 +2,8 @@
   <div id="rc-scroll-anchor"></div>
   <table>
     <thead>
-    <th class="th-pos">Position</th>
-    <th class="th-cat">Category</th>
+    <th class="th-pos">{{i18n "categories.reorder.position"}}</th>
+    <th class="th-cat">{{i18n "categories.category"}}</th>
     </thead>
     {{#each categoriesOrdered as |cat|}}
       <tr data-category-id="{{cat.id}}">

config/locales/client.en.yml

@@ -375,6 +375,7 @@ en:
         fix_order_tooltip: "Not all categories have a unique position number, which may cause unexpected results."
         save: "Save Order"
         apply_all: "Apply"
+        position: "Position"
       posts: "Posts"
       topics: "Topics"
       latest: "Latest"