[Feature request] add toLocaleString options for @vuepress/plugin-last-updated

[YunYouJun]

Feature request

add options config for @vuepress/plugin-last-updated

What problem does this feature solve?

In @vuepress/plugin-last-updated, toLocaleString is the default transformer.
toLocaleString has some options, so sometimes we don't need use custom transformer here.

Example: We just need pass { hour12: false } to get 24-hour.

What does the proposed API look like?

module.exports = {
  plugins: [
    [
      '@vuepress/last-updated',
      {
        options: {
          // more options
          // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/toLocaleString
          hour12: false
        }
      }
    ]
  ]
}

How should this be implemented in your opinion?

Add options param for defaultTransformer.

Are you willing to work on this yourself?

Yes.

[mishengqiang]

#2192 这个特性可能导致一些第三主题出现Invalid Date的错误，比如vuepress-theme-ououe主题。

相关的中文文档及时跟进，现在默认值还是undefined。

[kefranabg]

Has been fixed in 369c315 . Will be in the next release