feat: add GitHub CLI shell helper

Author: rismay

sources/common-shell/CommonShell+GitHubCLI.swift

@@ -0,0 +1,12 @@
+import CommonProcess
+import Foundation
+
+extension CommonShell {
+  /// Convenience for creating a shell bound to the GitHub CLI.
+  public static func gitHubCLI(
+    workingDirectory: String = FileManager.default.currentDirectoryPath,
+    hostKind: ExecutionHostKind? = .env(options: [])
+  ) -> CommonShell {
+    CommonShell(workingDirectory: workingDirectory, executable: .name("gh"), hostKind: hostKind)
+  }
+}