list-ops: update docs (#2150)

[no important files changed]

exercises/practice/list-ops/.docs/instructions.md

@@ -12,6 +12,8 @@ The precise number and names of the operations to be implemented will be track d
 - `filter` (*given a predicate and a list, return the list of all items for which `predicate(item)` is True*);
 - `length` (*given a list, return the total number of items within it*);
 - `map` (*given a function and a list, return the list of the results of applying `function(item)` on all items*);
-- `foldl` (*given a function, a list, and initial accumulator, fold (reduce) each item into the accumulator from the left using `function(accumulator, item)`*);
-- `foldr` (*given a function, a list, and an initial accumulator, fold (reduce) each item into the accumulator from the right using `function(item, accumulator)`*);
-- `reverse` (*given a list, return a list with all the original items, but in reversed order*);
+- `foldl` (*given a function, a list, and initial accumulator, fold (reduce) each item into the accumulator from the left*);
+- `foldr` (*given a function, a list, and an initial accumulator, fold (reduce) each item into the accumulator from the right*);
+- `reverse` (*given a list, return a list with all the original items, but in reversed order*).
+
+Note, the ordering in which arguments are passed to the fold functions (`foldl`, `foldr`) is significant.