added note, that spreadsheet library is being loaded

Signed-off-by: Stephan Richter <s.richter@srsoftware.de>

frontend/src/Components/MarkdownDisplay.svelte

@@ -1,5 +1,7 @@
 <script>
 	import { onMount, onDestroy } from 'svelte';
+	import { t } from '../translations.svelte';
+
 	let { classes='markdown', markdown=$bindable({source:'',rendered:''}), onclick = null, oncontextmenu = null, title='', wrapper = 'div' } = $props();
 	let jspreadsheet = null;
 	const regex = /@startsheet[\s\S]*?@endsheet/g;
@@ -29,15 +31,17 @@
 		if (!markdown.rendered) return;
 		let sheets = document.getElementsByClassName('spreadsheet');
 		for (let i = 0; i < sheets.length; i++) {
+			let sheet = sheets[i];
+			let raw = sheet.innerHTML.trim();
 			if (!jspreadsheet) {
+				sheet.innerHTML = t('Loading spreadsheet library…');
 				let module = await import('jspreadsheet-ce'); // path or package name
 				await import('jspreadsheet-ce/dist/jspreadsheet.css');
 				jspreadsheet = module.default ?? module;
 			}
 			if (!jspreadsheet) break; // break loop if library fails to load
+			sheet.innerHTML = t('Processing spreadsheet data…');
 
-			let sheet = sheets[i];
-			let raw = sheet.innerHTML.trim();
 
             // Use parseCSV from the helpers
             const parsed = jspreadsheet.helpers.parseCSV(raw, '|');