Replacing nodejs-repo-tools with synthtool

[jkwlui]

While most of the automated workflows for Node.js client libraries have mostly moved to synthtool, we still use the legacy @google-cloud/repo-tools package for dynamically generating README.md and samples/README.md based on what we have in the samples/ directory.

See nodejs-vision's samples/README.md

[JustinBeckwith]

Seems like this is something we would want for other languages too, no? Should we consider adding this to synthtool? @theacodes @busunkim96

[theacodes]

Yes, but let's start with Node.js.

[JustinBeckwith]

Context for others - repo-tools does a lot of things, and we've been slowly moving away towards single purpose tools. Maintaining it has been hard, and at this stage the only thing yoshi is using it for is generating READMEs that embed samples. It's causing hella trouble.

So here's what I think we should do. I want to do this slow like, and responsibly:

• Let's create a vnext branch in GoogleCloudPlatform/nodejs-repo-tools
• Essentially delete all the code in that branch and start from scratch
• Just have a very simple CLI that only does the README.md and samples/README.md manipulation
• Release this under a different npm dist-tag, so we don't hurt other sample repos still possibly using repo-tools
• If we decide we like this approach, we split this code out into a new repo, googleapis/readme-generator
• We try to make the readme generator work across all languages. No one off tools for just nodejs if it can at all be avoided

Looking for input on the approach here @broady @bcoe @crwilcox @busunkim96 @fhinkel ❤️

[fhinkel]

nodejs-docs-samples and nodejs-getting-started is still using many of the test commands and things like repo-tools.getRequest() in the test code.