feat: module improvements

[pi0]

• Avoid mentioning "Nuxt 3" in docs
• Allow bridge usage support as I couldn't any special feature not being supported
• Avoid building commonJS version as @nuxt/kit is ESM-only
• Enable CJS bridge to allow using __dirname
• Move runtime (plugin, composables) to runtime/ dir and ensure is transpiled
• Explicitly add all used dependencies. (Anything you do import should be in dependencies!)
• Only bypass known options to runtime config
• Read env in defaults
• Remove additional type refs. defineNuxtModule sets them for setup

Note: We probably need another iteration of improvements once module builder is available but it at least prepares module for this step.

[atinux]

Why not mentioning Nuxt 3?

[pi0]

We are not planning to fragment the ecosystem by introducing Nuxt3 branded modules! This is counter-effort at least not acceptable for modules being hosted in nuxt-community.