fix(deps): update dependency ngx-markdown to v19

Author: renovate[bot]

package.json

@@ -26,7 +26,7 @@
     "@angular/platform-browser-dynamic": "19.0.0",
     "@angular/router": "19.0.0",
     "marked": "^12.0.0",
-    "ngx-markdown": "^18.0.0",
+    "ngx-markdown": "^19.0.0",
     "prismjs": "^1.29.0",
     "rxjs": "~7.8.0",
     "tslib": "^2.3.0",