vite_rails: Improve default deployment and dev enviroment support

Rails 7.2+ ships with features like the ability to generate a [devcontainer](https://edgeguides.rubyonrails.org/getting_started_with_devcontainer.html) for development, [Github Action to run tests](https://github.com/rails/rails/issues/50502) and Rails 8 will ship with [Kamal](https://github.com/rails/rails/pull/51798) configured by default for deployment.

It would be helpful if vite_rails integrated into these systems automatically or (as a fallback) documented what steps users need to take in order to work with these new defaults.

At a first pass, I ran into trouble with:
* Github Action tests where vite wasn't installed (solved by manually adding `run: npm install`)
* Kamal, where npx wasn't installed
* Devcontainers - untested.

There are some pointers in the existing docs, like a dependency on npx and some notes about devcontainers port forwarding, but I think it would be helpful to have very clear steps for Rails users as part of the vite_rails setup docs.

For example, I'm not sure if I should actually be running `npm install` in my Github Action or if there's a bug somewhere in `vite:install_dependencies` or other hooks which should automatically install the deps.