Added missing translations

src/PixiEditor/Data/Localization/Languages/en.json

@@ -1144,5 +1144,9 @@
   "TOGGLE_FULLSCREEN": "Toggle Fullscreen",
   "TOGGLE_FULLSCREEN_DESCRIPTIVE": "Enter or Exit Fullscreen Mode",
   "SHORTCUTS_IMPORTED_WITH_ERRORS": "Importing shortcuts finished with errors.\nSome shortcuts were not recognized and have been skipped.",
-  "OPEN_ERROR_LOG": "Open error log"
+  "OPEN_ERROR_LOG": "Open error log",
+  "POSTERIZATION_NODE": "Posterize",
+  "LEVELS": "Levels",
+  "RGB_POSTERIZATION_MODE": "RGB",
+  "LUMINANCE_POSTERIZATION_MODE": "Luminance"
 }