Personal website localization

Context

I continued updating the personal website so it has separate Czech and English content versions.

Changes

• Added Czech versions of selected project pages.
• Updated the experience page for the English version.
• Added Czech variants of the Now and About pages.
• Added locale-specific CV downloads.
• Added WhatsApp and Discord links to contact areas and the header navigation.
• Hid the Writing section without removing the existing content.
• Added a Markdown-based journal without a database.
• Bought the sijanov.com domain and deployed the application there.

Notes

• Content is separated mainly through localized components and translation content collections.
• Some areas still contain temporary copied text and should be rewritten later.
• Local production URL changes were kept outside the individual PRs.