geneontology.github.io URL exposed in many cases where a "/" is not included at the end of the URL

I think this is unintentional, but trying to provide a user with a link to
> geneontology.org/docs/downloads#doi-versioned-bundles 

displays the address of 
> https://geneontology.github.io/docs/downloads/#doi-versioned-bundles

I think we wanted the .github.io bits hidden??  On FF 98.x

@kltm 