correct + extend description

Author: dcog989

Plugins/Flow.Launcher.Plugin.Calculator/plugin.json

@@ -2,7 +2,7 @@
   "ID": "CEA0FDFC6D3B4085823D60DC76F28855",
   "ActionKeyword": "*",
   "Name": "Calculator",
-  "Description": "Perform mathematical calculations (including hexadecimal values). Use ',' or '.' as thousand separator or decimal place.",
+  "Description": "Perform mathematical calculations, including hex values and advanced math functions, such as 'min(1,2,3)', 'sqrt(123)', 'cos(123)', etc.. User locale determines thousand separator and decimal place.",
   "Author": "cxfksword, dcog989",
   "Version": "1.0.0",
   "Language": "csharp",