Directory indexes

[ingydotnet]

We moved this content from an nginx server to github pages. Nginx provides directory content pages. We'll need to generate those now.

For example https://pyyaml.org/download/ is 404 but should be a directory index for https://github.com/yaml/pyyaml.org/tree/master/download

[ingydotnet]

@perlpunk See http://pyyaml.resolvent.net/download/ for original html

You should make the new html look like that.

Also if you could add a make update in a top level Makefile that would be awesome.

[perlpunk]

@ingydotnet Yes, I'll try to make it look like that. But I can't preserve the timestamp

[ingydotnet]

@perlpunk No worries on that. it doesn't need to match perfectly.

[ingydotnet]

@perlpunk Looks good. Closing this.