doc: add rest for data out

docs/en/09-data-out/02-rest.md

+---
+sidebar_label: REST
+title: REST
+description: Insert data using REST API
+---
+
+<!-- exclude -->
+import Tabs from '@theme/Tabs';
+import TabItem from '@theme/TabItem';
+
+<!-- exclude-end -->
+
+In this section we will explain how to query data from TDengine cloud service using REST API.
+
+## Config
+
+Run this command in your terminal to save the TDengine cloud token and URL as variables:
+
+<Tabs defaultValue="bash">
+<TabItem value="bash" label="Bash">
+
+```bash
+export TDENGINE_CLOUD_TOKEN="<token>"
+export TDENGINE_CLOUD_URL="<url>"
+```
+
+</TabItem>
+<TabItem value="cmd" label="CMD">
+
+```bash
+set TDENGINE_CLOUD_TOKEN="<token>"
+set TDENGINE_CLOUD_URL="<url>"
+```
+
+</TabItem>
+<TabItem value="powershell" label="Powershell">
+
+```powershell
+$env:TDENGINE_CLOUD_TOKEN="<token>"
+$env:TDENGINE_CLOUD_URL="<url>"
+```
+
+</TabItem>
+</Tabs>
+
+## Insert
+
+Following command below show how to insert data into the table `d1001` of the database `test` via the command line utility `curl`.
+
+```bash
+curl -L \
+  -d "select name, ntables, status from information_schema.ins_databases;" \
+  $TDENGINE_CLOUD_URL/rest/sql/test?token=$TDENGINE_CLOUD_TOKEN
+```
+
+Please refer to [REST-API](https://docs.tdengine.com/reference/rest-api/) for detailed documentation.