Fix walineJS related questions

[aozaki-kuro]

• fixed walineJS address (it's missing an @)
• added requiredMeta for config.toml to avoid spam

e.g.

# {{< version 0.2.0 >}} {{< link "https://waline.js.org/en/" "Waline" >}} comment config
      [params.page.comment.waline]
        enable = true
        serverURL = "https://xxx.vercel.app/"
        visitor = true
        dark = 'auto'
        requiredFields = ["nick", "mail"] # Use " to avoid errors

[victor-pogor]

@all-contributors please add @aozaki-kuro for bug, code

[allcontributors]

@victor-pogor

I've put up a pull request to add @aozaki-kuro! 🎉