Resolve "Blog localisation - XML sitemap errors"

Closes #168 (closed)

What changed and why?

• Develop a script to verify the sitemap.xml file and correctly generate localized sitemap URLs. This is essential because the application uses '/blog' as the base path, which requires the locale to be placed after '/blog' (e.g., '/blog/de-de/' instead of '/de-de/blog'). Currently, there is no straightforward method to achieve this using Vue/Nuxt.

Production	Review App
https://about.gitlab.com/blog/sitemap.xml	https://168-blog-localisation-xml-sitemap-errors.about.gitlab-review.app/blog/sitemap.xml