KT-20357 - Add sample for Regex.findAll()

libraries/stdlib/jvm/src/kotlin/text/regex/Regex.kt

@@ -121,6 +121,8 @@ internal constructor(private val nativePattern: Pattern) : Serializable {
 
     /**
      * Returns a sequence of all occurrences of a regular expression within the [input] string, beginning at the specified [startIndex].
+     *
+     * @sample samples.text.Regexps.findAll
      */
     @Suppress("ACTUAL_FUNCTION_WITH_DEFAULT_ARGUMENTS")
     public actual fun findAll(input: CharSequence, startIndex: Int = 0): Sequence<MatchResult> =