enhanceApp options should merge options we pass

Feature request

actually i am building additional page from components with docs

https://github.com/f3ltron/vuepress-plugin-docgen

// https://github.com/vuejs/vuepress/blob/master/packages/%40vuepress/core/lib/client/app.js#L88

const options = {}

  try {
    appEnhancers.forEach(enhancer => {
      if (typeof enhancer === 'function') {
        enhancer({ Vue, options, router, siteData, isServer })
      }
    })
  } catch (e) {
    console.error(e)
  }

  const app = new Vue(
    Object.assign(options, {
      router,
      render (h) {
        return h('div', { attrs: { id: 'app' }}, [
          h('router-view', { ref: 'layout' }),
          h('div', { class: 'global-ui' }, globalUIComponents.map(component => h(component)))
        ])
      }
    })
  )

What problem does this feature solve?

when we use some front plugin like vue18n in my case by letting me merge my options into options there will be no more bug for $t is not define

What does the proposed API look like?

The merge should merge dynamically our options

Are you willing to work on this yourself?

i can if it’s accepted

[MickaMx]

Yep, I saw that. It didn’t got merge yet ^^

[jsbaguette]

@meteorlxy answered to the question thx i am closing the issue