Add example of `enable-versioned-regex`

The readme shows usage of `enable-versioned-regex`, but it doesn't explain what this does or why it should be used.

Is the property required? If not, what is the default if omitted?

Start with the README section that demonstrates `enable-versioned-regex` and check the action configuration or documentation referenced there. Update the example's explanation to state whether the property is required and what default applies when it is omitted.

索引モデルが issue の本文から書いたものです。