Add frontend live / hot reload workflow

[ang-zeyu]

quick follow up to #1306

What is the purpose of this pull request? (put "X" next to an item, remove the rest)

• [x] Other, please explain: devops

What is the rationale for this request?
Speed up frontend development x1000

What changes did you make? (Give an overview)

• Added live / hot reload as a --dev / -d option to markbind serve
  • tested with different baseUrl configurations, and the -o options.
  • other options in markbind serve should be independent of this
• Added this to the dev guide workflow.md
• Modify the page template to not output the css asset link in development.
  • this is necessary as deleting some styles in development may not take effect since the style may still be present in the css bundle

Is there anything you'd like reviewers to focus on?
na

Testing instructions:
markbind s -d (with any other options)

Proposed commit message: (wrap lines at 72 characters)
Add frontend live / hot reload workflow

The frontend workflow requires launching webpack in watch mode. This is
then followed by manually copying the built bundles to the output
directory of the site, or terminating and then relaunching the MarkBind
command.

With a frontend entry point setup in the core-web package, and the
MarkBind /vue-strap fork merged into the main monorepo, let's take
advantage of this and add a live / hot reload workflow.
This provides a near instant edit-feedback development cycle that makes
frontend development much quicker.

This is integrated into the markbind serve command using the --dev
option.