feat(Kotlin): Replace value with _val (#1254)

* ci(kotlin): Add workflow file.

* Update kotlin.yml

* style(kotlin): value -> _val

---------

Co-authored-by: Yudong Jin <krahets@163.com>

codes/kotlin/chapter_hashing/hash_map.kt

@@ -44,7 +44,7 @@ fun main() {
         println(key)
     }
     println("\n单独遍历值 Value")
-    for (value in map.values) {
-        println(value)
+    for (_val in map.values) {
+        println(_val)
     }
 }