[docs] add info on accessing the playground via CLI (#10944)

* [docs] add info on accessing the playground via CLI

...and multiple available versions

* Update docs/en/getting-started/playground.md

Co-authored-by: Ilya Yatsishin <2159081+qoega@users.noreply.github.com>

Co-authored-by: Ilya Yatsishin <2159081+qoega@users.noreply.github.com>

docs/en/getting-started/playground.md

@@ -5,8 +5,31 @@ toc_title: Playground
 
 # ClickHouse Playground {#clickhouse-playground}
 
-[ClickHouse Playground](https://play.clickhouse.tech?file=welcome) allows people to experiment with ClickHouse by running queries instantly, without setting up their server or cluster.
+[ClickHouse Playground](https://play.clickhouse.tech) allows people to experiment with ClickHouse by running queries instantly, without setting up their server or cluster.
-Several example datasets are available in the Playground as well as sample queries that show ClickHouse features.
+Several example datasets are available in the Playground as well as sample queries that show ClickHouse features. There's also a selection of ClickHouse LTS releases to experiment with.
+
+ClickHouse Playground gives the experience of m2.small [Managed Service for ClickHouse](https://cloud.yandex.com/services/managed-clickhouse) instance hosted in [Yandex.Cloud](https://cloud.yandex.com/). More information about [cloud providers](../commercial/cloud.md).
+
+You can make queries to playground using any HTTP client, for example [curl](https://curl.haxx.se) or [wget](https://www.gnu.org/software/wget/), or set up a connection using [JDBC](../interfaces/jdbc.md) or [ODBC](../interfaces/odbc.md) drivers. More information about software products that support ClickHouse is available [here](../interfaces/index.md).
+
+## Credentials
+
+| Parameter         | Value                                   |
+|:------------------|:----------------------------------------|
+| HTTPS endpoint    | `https://play-api.clickhouse.tech:8443` |
+| Native endpoint   | `play-api.clickhouse.tech:9440`         |
+| User              | `playground`                            |
+| Password          | `clickhouse`                            |
+
+!!! note "Note"
+    Note that all endpoints require a secure TLS connection.
+
+There are additional endpoints with specific ClickHouse releases to experiment with their differences (ports and user/password are the same as above):
+
+* 20.3 LTS: `play-api-v20-3.clickhouse.tech`
+* 19.14 LTS: `play-api-v19-14.clickhouse.tech`
+
+## Limitations
 
 The queries are executed as a read-only user. It implies some limitations:
 
@@ -14,33 +37,28 @@ The queries are executed as a read-only user. It implies some limitations:
 -   INSERT queries are not allowed
 
 The following settings are also enforced:
-- [`max_result_bytes=10485760`](../operations/settings/query_complexity/#max-result-bytes)
+- [max_result_bytes=10485760](../operations/settings/query_complexity/#max-result-bytes)
-- [`max_result_rows=2000`](../operations/settings/query_complexity/#setting-max_result_rows)
+- [max_result_rows=2000](../operations/settings/query_complexity/#setting-max_result_rows)
-- [`result_overflow_mode=break`](../operations/settings/query_complexity/#result-overflow-mode)
+- [result_overflow_mode=break](../operations/settings/query_complexity/#result-overflow-mode)
-- [`max_execution_time=60000`](../operations/settings/query_complexity/#max-execution-time)
+- [max_execution_time=60000](../operations/settings/query_complexity/#max-execution-time)
 
-ClickHouse Playground gives the experience of m2.small
+## Examples
-[Managed Service for ClickHouse](https://cloud.yandex.com/services/managed-clickhouse)
-instance hosted in [Yandex.Cloud](https://cloud.yandex.com/).
-More information about [cloud providers](../commercial/cloud.md).
 
-ClickHouse Playground web interface makes requests via ClickHouse [HTTP API](../interfaces/http.md).
+HTTPS endpoint example with `curl`:
-The Playground backend is just a ClickHouse cluster without any additional server-side application.
-ClickHouse HTTPS endpoint is also available as a part of the Playground.
-
-You can make queries to playground using any HTTP client, for example [curl](https://curl.haxx.se) or [wget](https://www.gnu.org/software/wget/), or set up a connection using [JDBC](../interfaces/jdbc.md) or [ODBC](../interfaces/odbc.md) drivers.
-More information about software products that support ClickHouse is available [here](../interfaces/index.md).
-
-| Parameter | Value                                 |
-|:----------|:--------------------------------------|
-| Endpoint  | https://play-api.clickhouse.tech:8443 |
-| User      | `playground`                          |
-| Password  | `clickhouse`                          |
-
-Note that this endpoint requires a secure connection.
-
-Example:
 
 ``` bash
 curl "https://play-api.clickhouse.tech:8443/?query=SELECT+'Play+ClickHouse!';&user=playground&password=clickhouse&database=datasets"
 ```
+
+TCP endpoint example with [../interfaces/cli.md]:
+``` bash
+clickhouse client --secure -h play-api.clickhouse.tech --port 9440 -u playground --password clickhouse -q "SELECT 'Play ClickHouse!'"
+```
+
+## Implementation Details
+
+ClickHouse Playground web interface makes requests via ClickHouse [HTTP API](../interfaces/http.md).
+The Playground backend is just a ClickHouse cluster without any additional server-side application. As mentioned above, ClickHouse HTTPS and TCP/TLS endpoints are also publicly available as a part of the Playground, both are proxied through [Cloudflare Spectrum](https://www.cloudflare.com/products/cloudflare-spectrum/) to add extra layer of protection and improved global connectivity.
+
+!!! warning "Warning"
+    Exposing ClickHouse server to public internet in any other situation is **strongly not recommended**. Make sure it listens only on private network and is covered by properly configured firewall.