fix documentation for enum.filter (#359)

* fix documentation for enum.filter

fixes #358

* update stdlib code comment for enum.filter

docs/stdlib-enum.md

@@ -23,8 +23,8 @@ enum := import("enum")
   iterate and returns undefined if `x` is not enumerable.`
 - `filter(x, fn) => [object]`: iterates over elements of `x`, returning an
   array of all elements `fn` returns truthy for. `fn` is invoked with two
-  arguments: `key` and `value`. `key` is an int index if `x` is array. `key` is
-  a string key if `x` is map. It returns undefined if `x` is not enumerable.
+  arguments: `key` and `value`. `key` is an int index if `x` is array. It returns
+  undefined if `x` is not array.
 - `find(x, fn) => object`: iterates over elements of `x`, returning value of
   the first element `fn` returns truthy for. `fn` is invoked with two
   arguments: `key` and `value`. `key` is an int index if `x` is array. `key` is

stdlib/srcmod_enum.tengo

@@ -73,8 +73,7 @@ export {
   },
   // filter iterates over elements of `x`, returning an array of all elements `fn`
   // returns truthy for. `fn` is invoked with two arguments: `key` and `value`.
-  // `key` is an int index if `x` is array. `key` is a string key if `x` is map.
-  // It returns undefined if `x` is not enumerable.
+  // `key` is an int index if `x` is array. It returns undefined if `x` is not array.
   filter: func(x, fn) {
     if !is_array_like(x) { return undefined }