added test files for range and highlighting support

validation/for_range.fl

@@ -0,0 +1,17 @@
+$include <std.fl>
+
+
+function spark(int argc, str[] argv) -> int {
+    int a = 0;
+    int b = 3;
+
+    range a .. b as i up {
+        printi(i);
+    }
+
+    range b .. a as j down {
+        printi(j);
+    }
+
+	return 0;
+}

validation/for_range.fl.expect

@@ -0,0 +1,5 @@
+{
+	"arguments": [],
+	"output": ["0", "1", "2", "3", "2", "1"],
+	"should_fail": false
+}

vscode/syntaxes/firestorm.tmLanguage.json

@@ -23,7 +23,7 @@
       "patterns": [
         {
           "name": "keyword.control.firestorm",
-          "match": "\\b(if|else|while|loop|for|return|do|function|end|offset)\\b"
+          "match": "\\b(if|else|while|loop|for|return|do|function|end|offset|range|up|down)\\b"
         }
       ]
     },