Adding the playground back in

docs/en/playground.md

@@ -0,0 +1,45 @@
+---
+sidebar_label: Playground
+sidebar_position: 2
+keywords: [clickhouse, playground, getting, started, docs]
+description: The ClickHouse Playground allows people to experiment with ClickHouse by running queries instantly, without setting up their server or cluster.
+---
+
+# ClickHouse Playground {#clickhouse-playground}
+
+[ClickHouse Playground](https://play.clickhouse.com/play?user=play) allows people to experiment with ClickHouse by running queries instantly, without setting up their server or cluster.
+Several example datasets are available in 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).
+
+## Credentials {#credentials}
+
+| Parameter           | Value                              |
+|:--------------------|:-----------------------------------|
+| HTTPS endpoint      | `https://play.clickhouse.com:443/` |
+| Native TCP endpoint | `play.clickhouse.com:9440`         |
+| User                | `explorer` or `play`               |
+| Password            | (empty)                            |
+
+## Limitations {#limitations}
+
+The queries are executed as a read-only user. It implies some limitations:
+
+-   DDL queries are not allowed
+-   INSERT queries are not allowed
+
+The service also have quotas on its usage.
+
+## Examples {#examples}
+
+HTTPS endpoint example with `curl`:
+
+``` bash
+curl "https://play.clickhouse.com/?user=explorer" --data-binary "SELECT 'Play ClickHouse'"
+```
+
+TCP endpoint example with [CLI](../interfaces/cli.md):
+
+``` bash
+clickhouse client --secure --host play.clickhouse.com --user explorer
+```