Resolve: Add version number in menu

closes #221 (closed)

This implementation version was chosen over others because of:

• The minimal code 'footprint' (comparison);
• Older security concerns with full require of package.json (example) and
• The independence of how the serve script is started (example)

EDIT: Further research showed that the first approach exposed the package.json in the webpack build process as well. (No treeshaking in effect - my mistake...) For that reason the approach via vue.config.js was chosen (reference)