add language learner project

Dutch and Korean (explained in English) and English (explained in Dutch)
from A1 to C1, with a Hangul level for Korean. Lessons with notes, words
and sentences generate multiple-choice, typing, sentence building, cloze,
listening and matching exercises. Endless challenges: a seeded daily
challenge, sprint, survival, mixed practice, level tests, spaced-repetition
reviews and generated drills (numbers, clock times, de/het, plurals, Dutch
and Korean conjugation, particles, Hangul reading, irregular verbs).
Progress is stored in localStorage with export/import.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/lib/title.ts

@@ -29,6 +29,7 @@ export function getTitle(path: string, environment: SiteEnvironment = null): str
 		'/projects/derby': 'Derby Lens',
 		'/projects/cs-prices': 'CS Prices',
 		'/projects/game-tracker': 'Game Tracker',
+		'/projects/language-learner': 'Language Learner',
 		'/projects/money-tracker': 'Money Tracker',
 		'/projects/spotify-beatmap-finder': 'osu! map finder',
 		'/projects/progress': 'Progress',