Add map() documentation sample

* docs: add map() sample
* docs: add samples for Map and CharSequence
* docs: add another sample for Maps.map()

libraries/stdlib/samples/test/samples/collections/collections.kt

@@ -393,6 +393,12 @@ class Collections {
             assertPrints(chars.joinToString(limit = 5, truncated = "...!") { it.toUpperCase().toString() }, "A, B, C, D, E, ...!")
         }
 
+        @Sample
+        fun map() {
+            val numbers = listOf(1, 2, 3)
+            assertPrints(numbers.map { it * it }, "[1, 4, 9]")
+        }
+
         @Sample
         fun take() {
             val chars = ('a'..'z').toList()

libraries/stdlib/samples/test/samples/collections/maps.kt

@@ -277,7 +277,6 @@ class Maps {
             assertPrints(map2, "{beverage=2.7$, meal=12.4$}")
         }
 
-
         @Sample
         fun mapToSortedMap() {
             val map = mapOf(Pair("c", 3), Pair("b", 2), Pair("d", 1))
@@ -303,6 +302,16 @@ class Maps {
             assertPrints(props.getProperty("z", "fail"), "fail")
         }
 
+        @Sample
+        fun mapToList() {
+            val peopleToAge = mapOf("Alice" to 20, "Bob" to 21)
+            assertPrints(
+                peopleToAge.map { (name, age) -> "$name is $age years old" },
+                "[Alice is 20 years old, Bob is 21 years old]"
+            )
+            assertPrints(peopleToAge.map { it.value }, "[20, 21]")
+        }
+
     }
 
 }

libraries/stdlib/samples/test/samples/text/strings.kt

@@ -284,4 +284,10 @@ class Strings {
         assertPrints(string.dropLastWhile { !it.isLetter() }, "<<<First Grade")
     }
 
+    @Sample
+    fun map() {
+        val string = "kotlin"
+        assertPrints(string.map { it.toUpperCase() }, "[K, O, T, L, I, N]")
+    }
+
 }