update dumpling code example format (pingcap#8999) (pingcap#13866)

dumpling-overview.md

@@ -87,15 +87,7 @@ Dumpling exports data to SQL files by default. You can also export data to SQL f
 {{< copyable "shell-regular" >}}
 
 ```shell
-dumpling \
-  -u root \
-  -P 4000 \
-  -h 127.0.0.1 \
-  --filetype sql \
-  -t 8 \
-  -o /tmp/test \
-  -r 200000 \
-  -F 256MiB
+dumpling -u root -P 4000 -h 127.0.0.1 --filetype sql -t 8 -o /tmp/test -r 200000 -F 256MiB
 ```
 
 In the command above:
@@ -131,15 +123,7 @@ When you export data to CSV files, you can use `--sql <SQL>` to filter the recor
 {{< copyable "shell-regular" >}}
 
 ```shell
-./dumpling \
-  -u root \
-  -P 4000 \
-  -h 127.0.0.1 \
-  -o /tmp/test \
-  --filetype csv \
-  --sql 'select * from `test`.`sbtest1` where id < 100' \
-  -F 100MiB \
-  --output-filename-template 'test.sbtest1.{{.Index}}'
+./dumpling -u root -P 4000 -h 127.0.0.1 -o /tmp/test --filetype csv --sql 'select * from `test`.`sbtest1` where id < 100' -F 100MiB --output-filename-template 'test.sbtest1.{{.Index}}'
 ```
 
 In the command above:
@@ -262,12 +246,7 @@ Dumpling also supports reading credential files from `~/.aws/credentials`. Param
 {{< copyable "shell-regular" >}}
 
 ```shell
-./dumpling \
-  -u root \
-  -P 4000 \
-  -h 127.0.0.1 \
-  -r 200000 \
-  -o "s3://${Bucket}/${Folder}"
+./dumpling -u root -P 4000 -h 127.0.0.1 -r 200000 -o "s3://${Bucket}/${Folder}"
 ```
 
 ### Filter the exported data
@@ -279,12 +258,7 @@ By default, Dumpling exports all databases except system databases (including `m
 {{< copyable "shell-regular" >}}
 
 ```shell
-./dumpling \
-  -u root \
-  -P 4000 \
-  -h 127.0.0.1 \
-  -o /tmp/test \
-  --where "id < 100"
+./dumpling -u root -P 4000 -h 127.0.0.1 -o /tmp/test --where "id < 100"
 ```
 
 The above command exports the data that matches `id < 100` from each table. Note that you cannot use the `--where` parameter together with `--sql`.
@@ -296,14 +270,7 @@ Dumpling can filter specific databases or tables by specifying the table filter
 {{< copyable "shell-regular" >}}
 
 ```shell
-./dumpling \
-  -u root \
-  -P 4000 \
-  -h 127.0.0.1 \
-  -o /tmp/test \
-  -r 200000 \
-  --filter "employees.*" \
-  --filter "*.WorkOrder"
+./dumpling -u root -P 4000 -h 127.0.0.1 -o /tmp/test -r 200000 --filter "employees.*" --filter "*.WorkOrder"
 ```
 
 The above command exports all the tables in the `employees` database and the `WorkOrder` tables in all databases.