Sort modules in the stdlib api index in alphabetical order

[Octachron]

This PR patches the index files for the 4.13 to 5.0 API documentation to sort each link first by category:

• text tutorials
• stdlib and otherlibs modules
• internal stdlib modules

and then alphabetically inside each category.

cc @gasche

[sanette]

this should solve https://github.com/ocaml/v2.ocaml.org/issues/1617 https://github.com/ocaml/ocaml/issues/11478

however do I understand correctly that this has to be done manually at each new release? Couldn't this be integrated in the webman generation?

[Octachron]

Those are the index pages generated by ocamldoc after tweaking the input send to ocamldoc. There is no special manual process required fortunately.

[sanette]

oh great, thanks. out of curiosity, where is the "tweaking" done?

[Octachron]

https://github.com/ocaml/ocaml/pull/11860

[tmattio]

Thanks @Octachron!