"View source" but useful

(This may be an issue for `api.haxe.org` specifically.)

I would like the "View source" button for e.g. `sys.io.File` to be a dropdown menu showing these entries:

- the core API specification (https://github.com/HaxeFoundation/haxe/blob/development/std/sys/io/File.hx)
- the `eval` stubs (https://github.com/HaxeFoundation/haxe/blob/development/std/eval/_std/sys/io/File.hx)
- the `eval` source for `StdFile` (https://github.com/HaxeFoundation/haxe/blob/development/src/macro/eval/evalStdLib.ml#L980-L1051)
- similarly, the stubs or sources for other platforms

I realise the `eval` source linking is not trivial and would need some clever way to mark the position, ideally automatically generated from the latest `evalStdLib` file (search for `module StdFile = ` ... `end` ?)

Apart from that, dox should have enough information about the types and the various platform-specific files it has to merge.