🌐 feat(i18n): overhaul translation system & add languages (#145)

Revamp the existing translation system, simplifying
management and adding several new languages. The new system reads from
TOML files in the `/i18n` directory and improves template structures.
It also enhances customisation options and robustness by providing
fallbacks and modularity.

- Implement a new, streamlined translation macro.
- Load translations from `/i18n` TOML files.
- Remove redundant configuration requirements.
- Refactor templates to align with new i18n system.
- Add support for Hindi, Japanese, Russian, Portuguese, Chinese,
  Italian, German, Ukranian, Korean, and French languages.
- Credit Thomas Weitzel (@thomasweitzel) for inspiration.

templates/archive.html

@@ -5,7 +5,7 @@
 {{ macros_page_header::page_header(title=section.title) }}
 
 {# Set locale for date #}
-{% set date_locale = macros_translate::translate(key="date_locale", default="en_GB") %}
+{% set date_locale = macros_translate::translate(key="date_locale", default="en_GB", language_strings=language_strings) %}
 
 <div class="archive">
     <ul class="list-with-title">