docs(contributing): group os-specific code tabs (#15173)

CONTRIBUTING.md

@@ -11,7 +11,7 @@ Bun currently requires `glibc >=2.32` in development which means if you're on Ub
 
 Using your system's package manager, install Bun's dependencies:
 
-{% codetabs %}
+{% codetabs group="os" %}
 
 ```bash#macOS (Homebrew)
 $ brew install automake ccache cmake coreutils gnu-sed go icu4c libiconv libtool ninja pkg-config rust ruby
@@ -60,7 +60,7 @@ $ brew install bun
 
 Bun requires LLVM 16 (`clang` is part of LLVM). This version requirement is to match WebKit (precompiled), as mismatching versions will cause memory allocation failures at runtime. In most cases, you can install LLVM through your system package manager:
 
-{% codetabs %}
+{% codetabs group="os" %}
 
 ```bash#macOS (Homebrew)
 $ brew install llvm@18
@@ -97,7 +97,7 @@ $ which clang-16
 
 If not, run this to manually add it:
 
-{% codetabs %}
+{% codetabs group="os" %}
 
 ```bash#macOS (Homebrew)
 # use fish_add_path if you're using fish