Revert "Remove unused project name from export dialog (#2427)" (#2436)

src/locales/en.json

@@ -54,6 +54,7 @@
     "architect": "Architect",
     "artist": "Artist",
     "cartoonist": "Cartoonist",
+    "fileTitle": "File title",
     "colorPicker": "Color picker",
     "canvasBackground": "Canvas background",
     "drawingCanvas": "Drawing canvas",
@@ -62,6 +63,7 @@
     "language": "Language",
     "createRoom": "Share a live-collaboration session",
     "duplicateSelection": "Duplicate",
+    "untitled": "Untitled",
     "name": "Name",
     "yourName": "Your name",
     "madeWithExcalidraw": "Made with Excalidraw",