chore(*): update plugin default options && add examples

Signed-off-by: storyicon <yuanchao@bilibili.com>

examples/using-gogo/README.md

@@ -0,0 +1,28 @@
+# Using GoGo
+
+This example uses the following public libraries:
+* [googleapis](https://github.com/googleapis/googleapis)
+* [gogoproto](https://github.com/gogo/protobuf/tree/master/gogoproto)
+
+The following plug-ins are used:
+* [protoc-gen-gogo](github.com/gogo/protobuf/protoc-gen-gogo)
+* [protoc-gen-grpc-gateway](github.com/grpc-ecosystem/grpc-gateway)
+
+You can compile the proto file in this directory by executing the following command:
+```
+powerproto build -r ./apis
+```
+
+Not surprisingly, you will get the following output:
+```
+➜ tree
+.
+├── README.md
+├── apis
+│   ├── service.pb.go
+│   ├── service.pb.gw.go
+│   └── service.proto
+└── powerproto.yaml
+
+1 directory, 5 files
+```