[DATALAD RUNCMD] Update folder mapping for downloaded_data/non-UNFCCC

=== Do not change lines below ===
{
 "chain": [],
 "cmd": "python3 src/unfccc_ghg_data/helper/folder_mapping.py --folder=downloaded_data/non-UNFCCC",
 "dsid": "4d062170-604c-4efd-afbf-5ce7f97e0e63",
 "exit": 0,
 "extra_inputs": [],
 "inputs": [],
 "outputs": [
  "downloaded_data/non-UNFCCC/folder_mapping.json"
 ],
 "pwd": "."
}
^^^ Do not change lines above ^^^

downloaded_data/non-UNFCCC/folder_mapping.json

@@ -1,6 +1,7 @@
 {
     "CHL": "Chile",
+    "JPN": "Japan",
     "KOR": "Republic_of_Korea",
     "PSE": "PSE",
     "TWN": "Taiwan"
-}
+}