add eval libreoffice writer compare image & centering & check file existence

evaluation_examples/examples/libreoffice_writer/3ef2b351-8a84-4ff2-8724-d86eae9b842e.json

@@ -3,10 +3,35 @@
   "snapshot": "libreoffice_writer",
   "instruction": "center-justify the first line",
   "source": "https://askubuntu.com/questions/1066351/how-do-you-center-align-in-libreoffice#:~:text=Ctrl%20%2B%20e%20will%20Center%20align%20the%20cursor%20for%20you.",
-  "config": [],
+  "config": [
+    {
+      "type": "download",
+      "parameters": {
+        "files": [
+          {
+            "url": "https://drive.google.com/uc?export=download&id=1C8iti3eSCY8xWHzA_iUSNqNyj6Nop0Tbw8odSSFe83U",
+            "path": "Desktop/Centering_First_Line.docx"
+          }
+        ]
+      }
+    },
+    {
+      "type": "open",
+      "parameters": {
+        "path": "Desktop/Centering_First_Line.docx"
+      }
+    }
+  ],
   "trajectory": "trajectories/",
   "related_apps": [
     "libreoffice_writer"
   ],
-  "evaluator": "evaluation_dir"
-}
+  "evaluator": {
+    "func": "is_first_line_centered",
+    "result": {
+      "type": "vm_file",
+      "path": "Desktop/Centering_First_Line.docx",
+      "dest": "Centering_First_Line.docx"
+    }
+  }
+}