fix(cos): [139376671] tencentcloud_cos_buckets update doc (#3264)

* add

* add

Author: SevenEarth

.changelog/3264.txt

@@ -0,0 +1,3 @@
+```release-note:enhancement
+resource/tencentcloud_cos_buckets: update doc
+```

tencentcloud/services/cos/data_source_tc_cos_buckets.md

@@ -2,9 +2,19 @@ Use this data source to query the COS buckets of the current Tencent Cloud user.
 
 Example Usage
 
+Query all cos buckets
+
+```hcl
+data "tencentcloud_cos_buckets" "example" {}
+```
+
+Query cos buckets by filters
+
 ```hcl
-data "tencentcloud_cos_buckets" "cos_buckets" {
-  bucket_prefix      = "tf-bucket-"
-  result_output_file = "mytestpath"
+data "tencentcloud_cos_buckets" "example" {
+  bucket_prefix = "tf-example-prefix"
+  tags = {
+    createBy = "Terraform"
+  }
 }
-```
+```

website/docs/d/cos_buckets.html.markdown

@@ -13,10 +13,20 @@ Use this data source to query the COS buckets of the current Tencent Cloud user.
 
 ## Example Usage
 
+### Query all cos buckets
+
+```hcl
+data "tencentcloud_cos_buckets" "example" {}
+```
+
+### Query cos buckets by filters
+
 ```hcl
-data "tencentcloud_cos_buckets" "cos_buckets" {
-  bucket_prefix      = "tf-bucket-"
-  result_output_file = "mytestpath"
+data "tencentcloud_cos_buckets" "example" {
+  bucket_prefix = "tf-example-prefix"
+  tags = {
+    createBy = "Terraform"
+  }
 }
 ```