Add pdf export keyword to package.json

Co-authored-by: kdinev <[email protected]>

Author: Copilot

projects/igniteui-angular/package.json

@@ -40,6 +40,7 @@
         "drag drop",
         "drop down",
         "excel export",
+        "pdf export",
         "expansion panel",
         "grid",
         "hierarchical grid",