Add support for actions on / (index) route

[leonceaklin]

Describe the feature

I think it would be great if the library supports form actions on the / route via server/actions/index.ts. Currently this is not possible, because the parser recognizes index.ts as a form action for the route /index:

form-actions-nuxt/packages/form-actions-nuxt/src/runtime/utils.ts

Lines 5 to 10 in 4ba9695

	export function getActionRoute(actionPath: string) {
	const actionRegex = /.*actions[\/\\](.*?)\.ts/
	const actionRoute = actionRegex.exec(actionPath)?.[1]
	if (!actionRoute) throw new Error(`Could not parse action route from ${actionPath}`)
	return actionRoute
	}

Additional information

• Would you be willing to help implement this feature?