guides: LLVM 16 is now the default, so adjust the docs

Author: aykevl

content/docs/guides/build.md

@@ -49,7 +49,7 @@ For **Debian** or **Ubuntu** you can install LLVM by adding a new apt repository
 | Debian | sid    | `unstable`|
 
 ```shell
-echo 'deb http://apt.llvm.org/xxxxx/ llvm-toolchain-xxxxx-15 main' | sudo tee /etc/apt/sources.list.d/llvm.list
+echo 'deb http://apt.llvm.org/xxxxx/ llvm-toolchain-xxxxx-16 main' | sudo tee /etc/apt/sources.list.d/llvm.list
 ```
 
 After adding the apt repository for your distribution you may install the LLVM toolchain packages:
@@ -63,7 +63,7 @@ sudo apt-get install clang-16 llvm-16-dev lld-16 libclang-16-dev
 For **MacOS**, you can install LLVM through [Homebrew](https://formulae.brew.sh/formula/llvm). The Clang/LLVM version from Apple is not supported by TinyGo.
 
 ```shell
-brew install llvm
+brew install llvm@16
 ```
 
 For **Fedora** users you can install LLVM from the repository. Note that the version of LLVM [varies by Fedora version](https://packages.fedoraproject.org/pkgs/llvm/llvm-libs/), for example Fedora 37 has LLVM 15.