Add documentation section about runtime compilation for Vue v3

[skogowskinetfactory]

What problem does this feature solve?

Misconceptions about how the runtime compiler works, the difficulty in finding and combining information from other sections, vite (and things that are not in website documentation, but in readme.md - like the distribution files)

What does the proposed API look like?

Please add a documentation section about runtime compilation that would explain:

• how to enable runtime compilation in vite
• how the runtime compiler treats inner html of subcomponents (as a slot, even if the subcomponent doesn't use slots and doesn't have a template)
• how the runtime compiler treats inner html of mount point of root components (as a template, unless the component already have a template)
• how to pass properties to the root components when using runtime compiler

[skogowskinetfactory]

You can also add a section, that based on my research, one could probably use compile functions of Vue and precompile render functions outside of Vue and provide the ready render functions instead of html (which would result something between server side rendering and runtime compilation, this maybe would be useful for some people, me particularily)