fix: stack 미관상 수정

Author: acapzed

src/content/spec/about.md

@@ -31,12 +31,12 @@ into a structured plan and mindmap.
 
 # Stacks
 
-1Main:
+**Main** - 
 ![TypeScript](https://img.shields.io/badge/TypeScript-3178C6?style=flat&logo=typescript&logoColor=white)
 ![Rust](https://img.shields.io/badge/Rust-000000?style=flat&logo=rust&logoColor=white)
 ![Python](https://img.shields.io/badge/Python-3776AB?style=flat&logo=python&logoColor=white)
 
-ETC: 
+**ETC** - 
 ![Java](https://img.shields.io/badge/Java-ED8B00?style=flat&logo=openjdk&logoColor=white)
 ![Kotlin](https://img.shields.io/badge/Kotlin-7F52FF?style=flat&logo=kotlin&logoColor=white)
 ![Spring Boot](https://img.shields.io/badge/Spring_Boot-6DB33F?style=flat&logo=springboot&logoColor=white)