chore: added changelog for update modal

src/locales/en.json

@@ -8,6 +8,15 @@
       "order-list": "SAVED ORDERS",
       "order-train-picker": "TRAINS"
    },
+   "update": {
+      "update-available-text": "New GeneraTOR version is available!",
+      "update-available-underline": "Click here to update!",
+      "title": "Stacjownik update!",
+      "confirm": "ROGER THAT!",
+      "no-data": "No changelog available!",
+      "info-1": "This changelog will be available to see once again after clicking the version number in the footer",
+      "info-2": "The full app changelog available on <a href='https://github.com/Spythere/genera-tor' target='_blank'>the project's GitHub</a>"
+   },
    "order-message": {
       "title": "Message to display in the simulator's chatbox:",
       "info": "Copy or save the content of the generated train order using buttons below:",