Minor updates to examples (#85)

Rename "connect+grpc" to "connect-grpc" and add comments to Petstore protos to describe their origin and explain the package name.

Makefile

@@ -30,7 +30,7 @@ clean: ## Delete intermediate build artifacts
 test: build ## Run unit tests
 	$(GO) test -vet=off -race -cover ./...
 	cd internal/examples/pets && $(GO) test -vet=off -race -cover ./...
-	cd internal/examples/connect+grpc && $(GO) test -vet=off -race -cover ./...
+	cd internal/examples/connect-grpc && $(GO) test -vet=off -race -cover ./...
 
 .PHONY: build
 build: generate ## Build all packages

internal/examples/pets/internal/proto/io/swagger/petstore/v2/pets.proto

@@ -14,6 +14,15 @@
 
 syntax = "proto3";
 
+// The service defined herein comes from v2 of the Petstore service, which
+// is used as an example for Swagger/OpenAPI. The Swagger spec can be found
+// here: https://petstore.swagger.io/v2/swagger.json
+// A human-friendly HTML view of this API is also available at
+// https://petstore.swagger.io.
+//
+// This file defines only the "pet" service. The spec for this site also
+// includes "store" and "user" services which are not supported via these
+// RPC definitions.
 package io.swagger.petstore.v2;
 
 import "google/api/annotations.proto";