feat(completion): Add support for powershell completion (#1408)

This commit is to add support for powershell completion script.

Note: PowerShell v5.0+ is required

Author: sayboras

pkg/commands/completion.go

@@ -35,6 +35,13 @@ func (e *Executor) initCompletion() {
 		RunE:  e.executeFishCompletion,
 	}
 	completionCmd.AddCommand(fishCmd)
+
+	powerShell := &cobra.Command{
+		Use:   "powershell",
+		Short: "Output powershell completion script",
+		RunE:  e.executePowerShellCompletion,
+	}
+	completionCmd.AddCommand(powerShell)
 }
 
 func (e *Executor) executeBashCompletion(cmd *cobra.Command, args []string) error {
@@ -67,3 +74,12 @@ func (e *Executor) executeFishCompletion(cmd *cobra.Command, args []string) erro
 
 	return nil
 }
+
+func (e *Executor) executePowerShellCompletion(cmd *cobra.Command, args []string) error {
+	err := cmd.Root().GenPowerShellCompletion(os.Stdout)
+	if err != nil {
+		return errors.Wrap(err, "generate powershell completion")
+	}
+
+	return nil
+}