Add week 2 materials

materials/02-communication/grpc-practice/go-server/go.mod

@@ -0,0 +1,16 @@
+module hsegrpc
+
+go 1.20
+
+require (
+	google.golang.org/grpc v1.58.1
+	google.golang.org/protobuf v1.31.0
+)
+
+require (
+	github.com/golang/protobuf v1.5.3 // indirect
+	golang.org/x/net v0.12.0 // indirect
+	golang.org/x/sys v0.10.0 // indirect
+	golang.org/x/text v0.11.0 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20230711160842-782d3b101e98 // indirect
+)