feat: improve markdown component name

[privatenumber]

Problem

When using this plugin in conjunction with vite-plugin-pages, creating a markdown page with a specific name can cause component resolution issues with unplugin-vue-components.

For example, if I create a projects.md, behind the scenes, this plugin transforms it a component named "Projects". So when trying to auto-import the ~/components/Projects.vue component via <Projects /> using unplugin-vue-components, it doesn't work because Vue.js thinks I'm self-referencing the current page-component.

Feature request

To avoid this problem, I suggest implementing one of the following solutions:

• Add a "Md" or "Markdown" suffix to the component name to differentiate it from other components. For example, the component generated from projects.md would be named "ProjectsMd" or "ProjectsMarkdown".
  Add an option to configure the component name during transformation, so that users can customize the component name to suit their needs.

• I believe that implementing one of these solutions would resolve the issue and improve the user experience for those using these plugins together.

[antfu]

Yeah, I think it makes sense to have a better default and a custom function for users to customize the naming convention. PR welcome :)

[privatenumber]

Based on https://github.com/vuejs/core/blob/623ba514ec0f5adc897db90c0f986b1b6905e014/packages/compiler-sfc/src/compileScript.ts#L959, the only way to change the name seems to be adding:

<script>
export default { name: 'replace name' }
</script>

https://play.vuejs.org/#eNp9kTFPwzAQhf/K6ZYuVRDqFgoSoA4wAAJGL5ZzDSmObdnnEinKf8d21AAS6uZ73zvfO3vEW+eqYySscRuU7xxDII7uRhhlTWCQcA2XV8JsL2acQCqWMw3OeoaG9jJqhhGM7KmGlSenpaJSrmD6049r5JBu33dtdQjWpNmjMAACle1dp8k/O+7SdIE1FJKZ1Np+PRaNfaT1SVcfpD7/0Q9hyJrAF0+B/JEELoylb4lnvHt7oiGdF9jbJurkPgNfKVgdc8bZdhdNk2L/8pW0D31+nM6072E3MJlwWioHzc6p+AWmD7g/s/pP3E21KX3CTDh9AyUnkz8=

[brc-dd]

I had done something like this in VitePress: https://github.com/vuejs/vitepress/blob/1f4ae02138820f2ee78ce6ce39847cdfd0ba19ca/src/node/markdownToVue.ts#L314-L339

Similar stuff can be added here: https://github.com/mdit-vue/unplugin-vue-markdown/blob/f1ccc5f8751ce4020059b654219f9e55d17eec55/src/core/markdown.ts#L211-L232