[Bug] Convert Markdown to html not support chinese

[kamazheng]

My markdown index.md:

Covnerted:

        await DotnetApiCatalog.GenerateManagedReferenceYamlFiles(_configFile);
        await Docset.Build(_configFile);

{
  "$schema": "https://raw.githubusercontent.com/dotnet/docfx/main/schemas/docfx.schema.json",
  "metadata": [
    {
      "src": [
        {
          "src": "..",
          "files": [
            "**/*.csproj"
          ]
        }
      ],
      "dest": "api"
    }
  ],
  "build": {
    "content": [
      {
        "files": [
          "**/*.{md,yml}"
        ],
        "exclude": [
          "wwwroot/**"
        ]
      }
    ],
    "resource": [
      {
        "files": [
          "images/**"
        ]
      }
    ],
    "output": "wwwroot",
    "template": [
      "default",
      "modern"
    ],
    "globalMetadata": {
      "_appName": "Docker Api template",
      "_appTitle": "Docker Api template",
      "_enableSearch": true,
      "pdf": true
    }
  }
}

    <PackageReference Include="Docfx.App" Version="2.78.2" />
	  <PackageReference Include="Microsoft.CodeAnalysis.Workspaces.MSBuild" Version="4.11.0" />
	  <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="4.11.0" />

[kamazheng]

I update my file to be utf-8 encoding, that works.