This extensions adds syntax highlighting and bracket matching for .proto files (protobuf) in VS code. This extension is using this tmbundle: https://github.com/kevinweil/protobuf.tmbundle.
Launch Visual Studio code, press F1 and type ext install to bring up the list of extensions. Pick Protobuf support from the list to install the extension. Restart Visual Studio Code and you should be ready to go. Alternatively, you can copy the contents of the repo under ~/.vscode/extensions/vscode-protobuf.