5.1.0

[Feature] Optional react-router installation, + 2 misc fixes (0fb2c08)

There is now an additional prompt during yo enigma on whether you want to automatically have react-router set up. It will default to HTML5 pushstate-based routing, which budo is configured to support.

• Fixed static/index.html using relative paths when they should always be absolute to the serving root when using pushstate-based routing, since path nesting is an illusion.
• No longer using <main> as the React root, as semantically it may make more sense to be used deeper in the nested tree adjacent to a <header> or something similar.