Add anytools JSON + XML formatters (Transformation)

[D0bby999]

Two browser-based formatters for the Transformation section, inserted alphabetically.

• JSON Formatter & Validator — after JSON ABC
• XML Formatter / Validator — after WebAssembly Explorer

Both meet the CONTRIBUTING criteria:

• Browser-based — all processing is client-side, nothing is uploaded
• Direct link — each entry links straight to that tool, not to the site's landing page
• 100% free — no signup, no trial, no usage limit (the site has an optional account for saving favourites; every tool works fully without it)

Disclosure: I maintain anytools.world. Happy to drop either entry if you'd rather keep one tool per site.

[github-actions]

Hey D0bby999! Thanks for your submission! 🚀

To keep awesome-devtools instantly accessible for everyone, all tools must be:

• Browser-based — no downloads or native app installs
• Direct link — goes straight to the tool (not a multi-tool landing page)
• 100% free — no signups, trials, paywalls, or usage limits

Please make sure your PR meets these criteria. It may take some time for your submission to be reviewed — you can occasionally comment with a "bump" to bring more attention to it.

Thanks for contributing! 🙌