Add missing icon path

Author: SysC0mp

Plugins/HelloWorldFSharp/plugin.json

@@ -1,11 +1,12 @@
 {
-    "ID":"8FF5D5C1F8194958A12E8668FB7ECC04",
-    "ActionKeyword":"hf",
-    "Name":"Hello World FSharp",
-    "Description":"Hello World FSharp",
-    "Author":"Ioannis G.",
-    "Version":"1.0.0",
-    "Language":"fsharp",
-    "Website":"https://github.com/Flow-Launcher/Flow.Launcher",
-    "ExecuteFileName":"HelloWorldFSharp.dll"
+  "ID": "8FF5D5C1F8194958A12E8668FB7ECC04",
+  "ActionKeyword": "hf",
+  "Name": "Hello World FSharp",
+  "Description": "Hello World FSharp",
+  "Author": "Ioannis G.",
+  "Version": "1.0.0",
+  "Language": "fsharp",
+  "Website": "https://github.com/Flow-Launcher/Flow.Launcher",
+  "ExecuteFileName": "HelloWorldFSharp.dll",
+  "IcoPath": "app.png"
 }