I described function randomStringUTF8 (#146)

* I described function randomStringUTF8

* Update docs/en/sql-reference/functions/other-functions.md

Co-authored-by: BayoNet <da-daos@yandex.ru>

* Update docs/en/sql-reference/functions/other-functions.md

Co-authored-by: BayoNet <da-daos@yandex.ru>

* Update docs/en/sql-reference/functions/other-functions.md

Co-authored-by: BayoNet <da-daos@yandex.ru>

* Ive edited en-version and translated function description to Russian.

Co-authored-by: BayoNet <da-daos@yandex.ru>

docs/en/sql-reference/functions/other-functions.md

@@ -1200,4 +1200,41 @@ SELECT number, randomPrintableASCII(30) as str, length(str) FROM system.numbers
 └────────┴────────────────────────────────┴──────────────────────────────────┘
 ```
 
+## randomStringUTF8 {#randomstringutf8}
+
+Generates a random string of a specified length. Result string contains valid UTF-8 symbols.
+
+**Syntax**
+
+``` sql
+randomStringUTF8(length);
+```
+
+**Parameters**
+
+-   `length` — Required length of the resulting string in code points. [UInt64](../../sql-reference/data-types/int-uint.md).
+
+**Returned value(s)**
+
+-   UTF-8 random string.
+
+Type: [String](../../sql-reference/data-types/string.md).
+
+**Example**
+
+Query:
+
+```sql 
+SELECT randomStringUTF8(13)
+```
+
+Result:
+
+```text 
+┌─randomStringUTF8(13)─┐
+│ 𘤗𙉝д兠庇󡅴󱱎󦐪􂕌𔊹𓰛   │
+└──────────────────────┘
+
+```
+
 [Original article](https://clickhouse.tech/docs/en/query_language/functions/other_functions/) <!--hide-->

docs/ru/sql-reference/functions/other-functions.md

@@ -1153,4 +1153,41 @@ SELECT number, randomPrintableASCII(30) as str, length(str) FROM system.numbers
 └────────┴────────────────────────────────┴──────────────────────────────────┘
 ```
 
+## randomStringUTF8 {#randomstringutf8}
+
+Генерирует строку определенной длины со случайным набором валидных UTF-8-символов.
+
+**Синтаксис**
+
+``` sql
+randomStringUTF8(length);
+```
+
+**Параметры**
+
+-   `length` — Длина итоговой строки. [UInt64](../../sql-reference/data-types/int-uint.md).
+
+**Возвращаемое значение**
+
+-   Строка со случайными UTF-8-символами.
+
+Тип: [String](../../sql-reference/data-types/string.md).
+
+**Пример**
+
+Запрос:
+
+```sql 
+SELECT randomStringUTF8(13)
+```
+
+Результат:
+
+```text 
+┌─randomStringUTF8(13)─┐
+│ 𘤗𙉝д兠庇󡅴󱱎󦐪􂕌𔊹𓰛   │
+└──────────────────────┘
+
+```
+
 [Оригинальная статья](https://clickhouse.tech/docs/ru/query_language/functions/other_functions/) <!--hide-->