Add example grpcurl usage for Windows

Based on https://github.com/yidongnan/grpc-spring-boot-starter/issues/299#issuecomment-640500718

Also add a direct link to grpcurl in the trouble-shooting section

Author: ST-DDT

docs/en/server/getting-started.md

@@ -302,7 +302,10 @@ You can test that your application is working as expected by running these [grpc
 ````sh
 grpcurl --plaintext localhost:9090 list
 grpcurl --plaintext localhost:9090 list net.devh.boot.grpc.example.MyService
+# Linux (Static content)
 grpcurl --plaintext -d '{"name": "test"}' localhost:9090 net.devh.boot.grpc.example.MyService/sayHello
+# Windows or Linux (dynamic content)
+grpcurl --plaintext -d "{\"name\": \"test\"}" localhost:9090 net.devh.boot.grpc.example.MyService/sayHello
 ````
 
 ## Additional Topics <!-- omit in toc -->

docs/en/trouble-shooting.md

@@ -95,7 +95,8 @@ or (2) the target is not a grpc-server (e.g. a web-server).
    ````
 
    or remove the `negotiationType` config completely as `TLS` is the default.
-2. Validate that the configured server is running and is a grpc-server using `grpcurl` or a similar tool.
+2. Validate that the configured server is running and is a grpc-server using
+   [`grpcurl`](https://github.com/fullstorydev/grpcurl) or a similar tool.
 
 ## Could not find TLS ALPN provider