[Vuejs]-Create a documentation side-webapp for main app

My question is, is it possible to disable this route on production

You can create two entry points (so one more main.js) and in one of them add only the documentation route. Then configure the server to serve your second app under /documentation.

Or to have a second side project which only has this route

You could create some sort of “library” project containing your documentation and componends. Some tools to consider: lerna, bitsrc.io

Its pretty common to document components in storybook. You can easily create interactive, in-context demo scenarios. It is really simple to set up, but I’m not sure about possibilities of documenting classes.

Anyways, you’ve got some addresses to check, do some reading and you’ll be able to find something best suiting the needs of your case.