Server "cache" issues [mostly] with menu

API docs for all versions are generated as fully static html files, and that includes the top menu with its "versions" dropdown, haxe links etc.

Problem: `aws sync` [will not update the files if their size didn't change](https://github.com/aws/aws-cli/issues/3273), and most of the time the changes are changing a haxe version number or a commit sha, meaning the file size won't change, and the file isn't updated

A workaround would be to use `cp`, at least for `development` API docs which are the most sensitive (releases likely won't have changes outside the top menu once deployed). However, that would mean redeploying the whole API docs for `development` every time, which could hurt or aws quotas a bit (roughly 80MB every time).

Fixing everything would require to redeploy more than 2GB data, which would be pretty bad for our quotas, and which we would have to do again every time we modify the top menu...

We'll have to rework how the menu is handled..