Iterate on docs around CDN usage

[bencodezen]

The Problem

While there are docs that explain the limitation of single file components to build tools (and not CDN), there could be additional docs and language clarification to help people who may be coming in directly on techniques like script setup and trying to use that within the context of a CDN usage of Vue.

Proposed Solution

1. Analyze common entry points for techniques that rely on SFC compilation / compilers for opportunities to improve clarity around people who may be using a CDN solution.

[Z3rio]

If I am not wrong, script setup can't / shouldn't be used in Vue CDN.