Docs: Supply DELETE operation case in quick start

Author: pan3793

docs/quick_start/02_play_with_spark_sql.md

@@ -103,4 +103,13 @@ spark-sql> select * from test_db.tbl_sql;
 2022-02-02 10:10:10	2	2	2
 2022-02-02 10:10:10	2	2	2
 Time taken: 0.123 seconds, Fetched 6 row(s)
+
+spark-sql> delete from test_db.tbl_sql where id = 1;
+Time taken: 0.129 seconds
+
+spark-sql> select * from test_db.tbl_sql;
+2022-02-02 10:10:10	2	2	2
+2022-02-02 10:10:10	2	2	2
+2022-02-02 10:10:10	2	2	2
+Time taken: 0.101 seconds, Fetched 3 row(s)
 ```

docs/quick_start/03_play_with_spark_shell.md

@@ -98,6 +98,16 @@ scala> spark.table("test_db.tbl").show
 |2021-01-01 10:10:10|  1|  1|    1|
 |2022-02-02 10:10:10|  2|  2|    2|
 +-------------------+---+---+-----+
+
+scala> spark.sql("DELETE FROM test_db.tbl WHERE id=1")
+res3: org.apache.spark.sql.DataFrame = []
+
+scala> spark.table("test_db.tbl").show
++-------------------+---+---+-----+
+|        create_time|  m| id|value|
++-------------------+---+---+-----+
+|2022-02-02 10:10:10|  2|  2|    2|
++-------------------+---+---+-----+
 ```
 
 Execute ClickHouse native SQL.