Add list comprehension example to haskell/2010/control_structures.json

Adds a list_comprehension entry to haskell/2010/control_structures.json, bringing Haskell to feature-parity with Python and C# for this construct (see issue #774).

Author: DrCBeatz

web/thesauruses/haskell/2010/control_structures.json

@@ -62,6 +62,11 @@
       "not-implemented": true,
       "name": "Each iteration"
     },
+    "list_comprehension": {
+      "comment": "Second line adds a guard, which plays the same role as Python’s `if` filter.",
+      "code": "newList = [foo item | item <- iterable]\nnewList = [foo item | item <- iterable, conditional item]",
+      "name": "List Comprehension"
+    },
     "map_iteration": {
       "code": "map function list",
       "name": "Map iteration"