fix: add labels to options icon buttons for screen reader users

Change-Id: Ibc8ac61640b58c9d033ba05693050e4105271879
diff --git a/src/static/_locales/en/messages.json b/src/static/_locales/en/messages.json
index ac04853..8a603c7 100644
--- a/src/static/_locales/en/messages.json
+++ b/src/static/_locales/en/messages.json
@@ -59,6 +59,18 @@
     "message": "Languages:",
     "description": "Header of the selected languages list."
   },
+  "options_language_moveup": {
+    "message": "Move up",
+    "description": "Label for the button which lets a user move a language up the list."
+  },
+  "options_language_movedown": {
+    "message": "Move down",
+    "description": "Label for the button which lets a user move a language down the list."
+  },
+  "options_language_remove": {
+    "message": "Remove",
+    "description": "Label for the button which lets a user remove a language from the list."
+  },
   "options_otheroptionsheader": {
     "message": "Other options:",
     "description": "Subheader in the options page before the options to choose where should the translation be shown.."