v1.0.0: add header & footer

v1.0.0: add header & footer

We design an adaptive navigation component MyHeader with NavMenu component of Element UI and Nested Routes of Vue Router.

GitHub: https://github.com/sylvanding/covid19-self-triage

Docs: http://sylvanding.github.io/covid19-self-triage

What's New

1. add an adaptive navigation bar based on nested routes in vue router
2. add a footer card to show basic information and links for the website
3. add MyHeader&Footer introduction page in docs

Bug Fixes

• improve all less styles by restricting the scope of the selector. For example, importing a less file in component A will not affect the style of component B

Contributors

@sylvanding
@LelouchCcCC