Synchronizes 72 lesson files across 5 languages (de, pl, es, ar, uk) to match
the English source. This ensures code, solutions, and validations are identical
while only title, description, task, and message fields are translated.
Changes include:
- Box model lessons (01-box-model.json)
- Units and variables (05-units-variables.json)
- Transitions and animations (06-transitions-animations.json)
- Responsive design (08-responsive.json)
- HTML elements (20-html-elements.json)
- HTML forms basic and validation (21, 22)
- HTML details/summary, progress/meter (23, 24)
- HTML datalist, dialog, fieldset (25, 27, 28)
- HTML tables and SVG (30, 32)
- HTML marquee (31)
- Welcome module (00-welcome.json)
Fixes validation inconsistencies and removes extra content that exceeded
English source. German translations were largely correct; Polish, Spanish,
Arabic, and Ukrainian required full translations.
- Fixed validation in welcome lesson (Hello World instead of Hello)
- Replaced 'quoted text' with <code>quoted text</code> in all task descriptions
- Added syntax examples to Transitions and Keyframes lessons
- Updated all language versions (en, de, pl, es, ar, uk)
- Shorten German module titles with consistent HTML/CSS prefixes
- Add .completion-badge styling for the lesson title completion badge
- Make sidebar lessons section fill available height on desktop
- Improve flexbox lesson descriptions with more context
- Wrap HTML element names in <kbd> tags in all validation messages
- Apply consistent formatting to both English and German lessons
- Make hints clearer about which elements/attributes to use
- Fix mobile editor layout overflow issue
