docs: refine rest and schemaless doc (#17046)

* docs: add schemaless writing for cloud

* docs: add section description and remove http from url

* docs: adjust schemaless and rest api doc

* docs: refine rest api and schemaless doc

docs/en/07-data-in/05-rest-schemaless.md

@@ -55,3 +55,4 @@ curl -L \
   $TDENGINE_CLOUD_URL/rest/sql/test?token=$TDENGINE_CLOUD_TOKEN
 ```
 
+Please refer to [REST-API](https://docs.tdengine.com/reference/rest-api/) for detailed documentation.

docs/en/07-data-in/30-schemaless-influxdb.md

 ---
-sidebar_label: Schemaless - InfluxDB Line Protocol
+sidebar_label: InfluxDB Line Protocol
 title: Schemaless - InfluxDB Line Protocol
 description: Insert data in Schemaless Line Protocol
 ---

docs/en/07-data-in/35-schemaless-opentsdb-json.md

 ---
-sidebar_label: Schemaless - OpenTSDB JSON Protocol
+sidebar_label: OpenTSDB JSON Protocol
 title: Schemaless - OpenTSDB JSON Protocol
 description: Insert data in OpenTSDB JSON Protocol
 ---

docs/en/07-data-in/38-schemaless-opentsdb-telnet.md

 ---
-sidebar_label: Schemaless - OpenTSDB Telnet Protocol
+sidebar_label: OpenTSDB Telnet Protocol
 title: Schemaless - OpenTSDB Telnet Protocol
 description: Insert data in OpenTSDB Telnet Protocol
 ---