docs(chapter12): marked chapter 12 as complete

s3ich4n · s3ich4n · commit 58c9188503c5 · 2025-04-22T01:06:59.000+09:00
diff --git a/README.md b/README.md
@@ -15,7 +15,7 @@
 - [x] Chapter 09
 - [x] Chapter 10
 - [x] Chapter 11
-- [ ] Chapter 12
+- [x] Chapter 12
 
 # Preface
 
