docs: update README.md

README.md

@@ -1,20 +1,26 @@
 ## Just tinkering with grpc
 
-
 ### Setup
+
 ```
 docker-compose up
+
+# add two numbers and get the result
 curl localhost:3001/add/3/2
 ```
 
 ### Test mock server
+
+Actually mocking the server for testing...
+
 ```
 cd ./server
 go test
 ```
+
 ### To generate grpc code using protobuf compiler
 
 ```sh
-cd ./pd
+cd ./pb
 protoc --go_out=. --go-grpc_out=. calc_service.proto
 ```