Merge pull request #788 from daikiojm/adding-readme-directories-link

docs(readme): add packages directory link

Author: murgatroid99

README.md

@@ -35,15 +35,15 @@ This library loads `.proto` files into objects that can be passed to the gRPC li
 
 ### gRPC Tools
 
-Directory: `packages/grpc-tools`
+Directory: [`packages/grpc-tools`](https://github.com/grpc/grpc-node/tree/master/packages/grpc-tools)
 
 npm package: [grpc-tools](https://www.npmjs.com/package/grpc-tools)
 
 Distribution of protoc and the gRPC Node protoc plugin for ease of installation with npm.
 
 ### gRPC Health Check Service
 
-Directory: `packages/grpc-health-check`
+Directory: [`packages/grpc-health-check`](https://github.com/grpc/grpc-node/tree/master/packages/grpc-health-check)
 
 npm package: [grpc-health-check](https://www.npmjs.com/package/grpc-health-check)