add data source for dialog

data/dialog.json

@@ -0,0 +1,20 @@
+{
+  "description": "The file is shown in an interactive TUI dialog, thus it is not suitable for binary/too big data.",
+  "functions": {
+    "file-read": [
+      {
+        "code": "dialog --textbox \"[file]\" 0 0\n"
+      }
+    ],
+    "suid": [
+      {
+        "code": "./dialog --textbox \"[file]\" 0 0\n"
+      }
+    ],
+    "sudo": [
+      {
+        "code": "sudo dialog --textbox \"[file]\" 0 0\n"
+      }
+    ]
+  }
+}