This is the root. (./index.html)
The other files in this deploy are:
./foo.html
./bar/index.html
NOTE: for this case, you have to uncheck "Disable asset optimization" then uncheck "Pretty URLs"
/foo.html - Resolves to file contents - Anchor target in DOM still /foo.html (not re-written)
/foo - Resolves to file contents
/foo/ - Resolves to file contents
/bar.html - Resolves to file contents - Anchor target in DOM still /bar.html (not re-written)
/bar - Resolves to file contents
/bar/ - Resolves to file contents
This does not historical web parlance of document vs. directory-index for trailing slashes
This can be bad for SEO (content duplicated across trailing slash and non-trailing-slash variants)