Feature: download specification (#12)

* feat: download specification

* refactor: json key's properties

* feat: additional param in json config

* remove: forex from json specification

iqfeed.json

@@ -11,5 +11,37 @@
     ],
     "data-supported": [ "Equity", "Equity Options", "Futures" ], 
     "documentation": "/docs/v2/lean-cli/datasets/iqfeed",
-    "more-information": "https://www.iqfeed.net/index.cfm?displayaction=data&section=main"
+    "more-information": "https://www.iqfeed.net/index.cfm?displayaction=data&section=main",
+    "module-specification": {
+        "download": {
+            "data-types": [
+                "Trade",
+                "Quote"
+            ],
+            "resolutions": [
+                "Tick",
+                "Second",
+                "Minute",
+                "Hour",
+                "Daily"
+            ],
+            "security-types": [
+                "Equity",
+                "Option",
+                "Future"
+            ],
+            "markets": [
+                "USA",
+                "CME",
+                "NYMEX",
+                "SGX",
+                "Globex",
+                "COMEX",
+                "CBOT",
+                "CBOE",
+                "ICE",
+                "CFE"
+            ]
+        }
+    }
 }