Fix Accessibility and SEO Lighthouse scores

[km333]

What problem does this feature solve?

Hi,
Using 3.0.0-beta.15 I have created a new PWA app and immediately wanted to see the Lighthouse scores as this is something important to me. I got very good scores for Performance (94), Progressive Web App (91), Best Practices (94).
But a poor score for Accessibility (62) and SEO (? Errors).
I think it would be a quick win for the Vue team to fix these two up so everything is high when your users create a new project.
Cheers

What does the proposed API look like?

Accessibility main problems:
Image elements do not have [alt] attributes
Background and foreground colors do not have a sufficient contrast ratio

element does not have a [lang] attribute

SEO Main problems:
Document does not have a meta description
Document doesn't have a valid hreflang
Document does not have a valid rel=canonical
Page has unsuccessful HTTP status code
Page is blocked from indexing

[yyx990803]

Accessibility and SEO are completely determined by the content you end up building - the score of the demo app is irrelevant since no one's gonna ship that as their actual app, it's going to be replaced by your content.