hugo.yaml from toml config, preserving comments

[chalin]

• Fixes Convert config file to yaml #226
• Adds hugo.yaml generated from hugo.toml
• Infrastructure: moves cSpell config out of .vscode directory, and converts it to YAML too
• Keeps the old TOML config as hugo-disabled.toml for easier local side-by-side comparison. We'll delete it later.
• The generated example site files are the same.

[BrentHuang]

Why not just keep using hugo.toml?