fix(vpn): [138463021] tencentcloud_vpn_connections update code and doc (#3272)

* add

* add

Author: SevenEarth

.changelog/3272.txt

@@ -0,0 +1,3 @@
+```release-note:enhancement
+datasource/tencentcloud_vpn_connections: update code and doc
+```

tencentcloud/services/vpn/data_source_tc_vpn_connections.go

@@ -326,6 +326,7 @@ func dataSourceTencentCloudVpnConnectionsRead(d *schema.ResourceData, meta inter
 		mapping := map[string]interface{}{
 			"id":                         *connection.VpnConnectionId,
 			"name":                       *connection.VpnConnectionName,
+			"vpc_id":                     *connection.VpcId,
 			"vpn_gateway_id":             *connection.VpnGatewayId,
 			"customer_gateway_id":        *connection.CustomerGatewayId,
 			"ike_proto_authen_algorithm": *connection.IKEOptionsSpecification.PropoAuthenAlgorithm,

tencentcloud/services/vpn/data_source_tc_vpn_connections.md

@@ -2,15 +2,23 @@ Use this data source to query detailed information of VPN connections.
 
 Example Usage
 
+Query all vpn connections
+
+```hcl
+data "tencentcloud_vpn_connections" "example" {}
+```
+
+Query vpn connections by filters
+
 ```hcl
-data "tencentcloud_vpn_connections" "foo" {
-  name                = "main"
-  id                  = "vpnx-xfqag"
+data "tencentcloud_vpn_connections" "example" {
+  name                = "tf-example"
+  id                  = "vpnx-fq4e4364"
   vpn_gateway_id      = "vpngw-8ccsnclt"
-  vpc_id              = "cgw-xfqag"
-  customer_gateway_id = ""
+  vpc_id              = "vpc-6ccw0s5l"
+  customer_gateway_id = "cgw-r1g6c8fr"
   tags = {
-    test = "tf"
+    createBy = "Terraform"
   }
 }
-```
+```

website/docs/d/vpn_connections.html.markdown

@@ -13,15 +13,23 @@ Use this data source to query detailed information of VPN connections.
 
 ## Example Usage
 
+### Query all vpn connections
+
+```hcl
+data "tencentcloud_vpn_connections" "example" {}
+```
+
+### Query vpn connections by filters
+
 ```hcl
-data "tencentcloud_vpn_connections" "foo" {
-  name                = "main"
-  id                  = "vpnx-xfqag"
+data "tencentcloud_vpn_connections" "example" {
+  name                = "tf-example"
+  id                  = "vpnx-fq4e4364"
   vpn_gateway_id      = "vpngw-8ccsnclt"
-  vpc_id              = "cgw-xfqag"
-  customer_gateway_id = ""
+  vpc_id              = "vpc-6ccw0s5l"
+  customer_gateway_id = "cgw-r1g6c8fr"
   tags = {
-    test = "tf"
+    createBy = "Terraform"
   }
 }
 ```