feat: add zshellcheck formula

Formula/zshellcheck.rb

@@ -0,0 +1,33 @@
+class Zshellcheck < Formula
+  desc "Static analysis and auto-fix for Zsh scripts"
+  homepage "https://github.com/afadesigns/zshellcheck"
+  license "MIT"
+
+  if Hardware::CPU.arm?
+    url "https://github.com/afadesigns/zshellcheck/releases/download/v1.8.0/zshellcheck_Darwin_arm64.tar.gz"
+    sha256 "180879dc1fcd106dda667efa070af3829a38b736c23df1a6e7d9a527787d4038"
+  else
+    url "https://github.com/afadesigns/zshellcheck/releases/download/v1.8.0/zshellcheck_Darwin_x86_64.tar.gz"
+    sha256 "d097a48e93b7a77f6e0ca3c72a4f6aef9c7330963117fe2b1f394f682a651f6e"
+  end
+
+  livecheck do
+    url :homepage
+    strategy :github_latest
+  end
+
+  depends_on :macos
+
+  def install
+    bin.install "zshellcheck"
+    man1.install "man/man1/zshellcheck.1"
+    bash_completion.install "completions/bash/zshellcheck-completion.bash" => "zshellcheck"
+    zsh_completion.install "completions/zsh/_zshellcheck"
+  end
+
+  test do
+    assert_match version.to_s, shell_output("#{bin}/zshellcheck --version")
+    (testpath/"t.zsh").write "echo $x\n"
+    assert_match "ZC1075", shell_output("#{bin}/zshellcheck t.zsh", 1)
+  end
+end