feat: image support

also translated some strings back into english

WebApp/wwwroot/js/eventCreate.js

@@ -14,6 +14,7 @@ function createEvent() {
         const title = document.getElementById('title').value;
         const location = document.getElementById('location').value;
         const description = document.getElementById('description').value;
+        const imageURL = document.getElementById('imageURL').value;
         const eventDateRaw = document.getElementById('eventDate').value;
         // Walidacja prostych pól
         if (!title || !location || !eventDateRaw) {
@@ -25,6 +26,7 @@ function createEvent() {
             title,
             location,
             description,
+            imageURL,
             eventDate,
         };
         try {