feat: add first element bar related strings

Author: devvaannsh

src/nls/root/strings.js

@@ -209,6 +209,9 @@ define({
     "LIVE_DEV_INSERT_SHOW_MORE": "Show more",
     "LIVE_DEV_INSERT_SHOW_LESS": "Show less",
     "LIVE_DEV_INSERT_CREATE": "Create",
+    "LIVE_DEV_EMPTY_CANVAS_LABEL": "Your page is empty — add an element",
+    "LIVE_DEV_EMPTY_CANVAS_ADD": "Add your first element",
+    "LIVE_DEV_EMPTY_CANVAS_COLLAPSE": "Collapse",
     "LIVE_DEV_EDIT_ONBOARD_TITLE": "Two new ways to edit",
     "LIVE_DEV_EDIT_ONBOARD_INSERT": "Add new HTML elements",
     "LIVE_DEV_EDIT_ONBOARD_PROPS": "Edit tag, classes, ID and attributes",