Enhancement: Allow specifying the index file name

[furkanb]

In SvelteKit each page is defined by a +page.svelte file. E.g.:
src/routes/blog/[slug]/+page.svelte or src/routes/blog/[slug]/+page[.md / .mdx / .svx] since we're using MDsveX.

When creating content with the FrontMatter extension the default file is named index.md. This requires the SvelteKit end user having to rename the file to +page.md so that SvelteKit can direct the route to the specified markdown file.

---

Assuming we have the following set on fronmatter.json

{
"frontMatter.taxonomy.contentTypes": [
    {
      "name": "default",
      "pageBundle": true,
      "fileType": "svx",
      …
    }
  ],
  "frontMatter.content.pageFolders": [
    {
      "title": "blog",
      "path": "[[workspace]]/src/routes/blog",
      "filePrefix": ""
    }
  ]
}

One idea could be to be able to associate a default file name string (which defaults to index) for each content type. Like so:

"frontMatter.taxonomy.contentTypes": [
    {
      "name": "default",
      "pageBundle": true,
      "fileType": "svx",
      "defaultFileName": "+page",      <---
      …
    }
  ]

Another idea could be to associate the default file name with a specific folder:

  "frontMatter.content.pageFolders": [
    {
      "title": "blog",
      "path": "[[workspace]]/src/routes/blog",
      "filePrefix": "",
      "defaultFileName": "+page"      <---
    }
  ]
}

[estruyf]

Thank you @furkanb, makes a lot of sense to add this support.

Question: should the defaultFileName property you propose, include the file extension?

[furkanb]

@estruyf If the default file name will be defined within the content type (frontMatter.taxonomy.contentTypes) I think it would be redundant to include the file extension since there's already a fileType property. So I would suggest defining the default file name property within the content type, this way the user could have the option to change either the file name or the file type.