Sorry to necropost, but I would also like this feature, and my googling came up
short.  This thread appears to be the most relevant reference to this feature
request.

I am using httrack to create a static version of a Wordpress site.  I can't
take credit for the idea:
<https://thehackerblog.com/the-unhackable-wordpress-blog-finding-security-in-the-static/index.html>

I am hosting the site on S3 and fronting it with CloudFront, and S3 websites
auto convert / to /index.html.  

So for example visiting:
<http://www.example.com/foo/>

Will load the index.html file without needing to reference it, and this keeps
things clean (as if the site is still running Wordpress).