Fix writing of example entry (JabRef#12940)

* Fix writing of example entry

* Fix line break

Author: koppor

src/main/java/org/jabref/gui/maintable/MainTable.java

@@ -587,15 +587,17 @@ private void updatePlaceholder(VBox placeholderBox) {
 
     private BibEntry addExampleEntry() {
         BibEntry exampleEntry = new BibEntry(StandardEntryType.Article)
-                .withField(StandardField.AUTHOR, "Oliver Kopp and Carl Christian Snethlage and Christoph Schwentker").withField(StandardField.TITLE, "JabRef: BibTeX-based literature management software")
+                .withField(StandardField.AUTHOR, "Oliver Kopp and Carl Christian Snethlage and Christoph Schwentker")
+                .withField(StandardField.TITLE, "JabRef: BibTeX-based literature management software")
                 .withField(StandardField.JOURNAL, "TUGboat")
                 .withField(StandardField.VOLUME, "44")
                 .withField(StandardField.NUMBER, "3")
                 .withField(StandardField.PAGES, "441--447")
                 .withField(StandardField.DOI, "10.47397/tb/44-3/tb138kopp-jabref")
                 .withField(StandardField.ISSN, "0896-3207")
                 .withField(StandardField.ISSUE, "138")
-                .withField(StandardField.YEAR, "2023");
+                .withField(StandardField.YEAR, "2023")
+                .withChanged(true);
 
         database.getDatabase().insertEntry(exampleEntry);
         return exampleEntry;