Adds coll as structural

Author: JJ

doc/Language/operators.pod6

@@ -31,7 +31,7 @@ tightest to loosest:
     X | Junctive and     |   &
     X | Junctive or      |   \| ^
     L | Named unary      |   temp let
-    N | Structural infix |   but does <=> leg unicmp cmp .. ..^ ^.. ^..^
+    N | Structural infix |   but does <=> leg unicmp cmp coll .. ..^ ^.. ^..^
     C | Chaining infix   |   != == < <= > >= eq ne lt le gt ge ~~ === eqv !eqv =~=
     X | Tight and        |   &&
     X | Tight or         |   \|\| ^^ // min max