Markdown plugin name only works in the short-hand form

[vojtapol]

• I confirm that this is an issue rather than a question.

Bug report

Steps to reproduce

When configuring Markdown and requesting a plugin to be used like this:

markdown: {
  plugins: [
    'markdown-it-abbr'
  ]
}

The abbreviations are ignored.

However, this configuration works as desired:

markdown: {
  plugins: [
    'abbr'
  ]
}

What is expected?

Both markdown-it-abbr and abbr in the plugin section should have the same effect as according to the documentation omitting the markdown-it- portion of the plugin name is optional.

What is actually happening?

Only the shorthand form works.

Other relevant information

My package.json:

{
  "name": "wiki",
  "version": "1.0.0",
  "private": true,
  "scripts": {
    "docs:dev": "vuepress dev docs",
    "docs:build": "vuepress build docs"
  },
  "devDependencies": {
    "@vuepress/plugin-back-to-top": "^1.4.0",
    "markdown-it-abbr": "^1.0.4",
    "vuepress": "^1.4.0"
  }
}

[meteorlxy]

Thanks for report.

[meteorlxy]

Ref #2175