add file read and write for lwp-download

data/lwp-download.json

@@ -15,6 +15,17 @@
       {
         "code": "sudo lwp-download [url] [file]\n"
       }
+    ],
+    "file-read": [
+      {
+        "description": "The file path must be absolute.",
+        "code": "TF=$(mktemp)\nlwp-download \"file://[file]\" $TF\ncat $TF\n"
+      }
+    ],
+    "file-write": [
+      {
+        "code": "TF=$(mktemp)\necho [data] >$TF\nlwp-download file://$TF [file]\n"
+      }
     ]
   }
-}
+}