We definitely welcome feedback and contribution to Google APIs! Here is some guideline and information about how to do so.
In order to protect both you and ourselves, you will need to sign the Contributor License Agreement.
You will need several tools to work with this repository. At minimum, you need both Protocol Buffers and gRPC in order to compile this repository and generate client library source code in various programming languages.
To compile the generated code into usable client libraries, you will need to use appropriate development environments and setup proper build configurations.
Currently, the root's Makefile only lets you generate source code for the client library in the programming languages supported by gRPC. It does not generate the ready-to-use client libraries yet.