[ocaml-infra] opam.ocaml.org/ocaml.org merge

[David Sheets]

Hello, world!

We have gathered here at the confluence of two great rivers:
opam.ocaml.org and ocaml.org. They meet here and flow on,
indistinguishable and majestic to the sea. Please join me on the bank
and bathe in the healing waters of...

OPAM.OCAML.ORG

<https://github.com/ocaml/opam2web/pull/113>

A number of things are slightly broken:

- I didn't port the CSS rules to center the buttons on the Home page.
- I had to disable the affix feature of the Documentation and Blog
sidebars (see <https://github.com/dsheets/opam2web/commit/9fa8b1cc142a2a287876cc69e15e40e066b33a41>).

Your comments and patches are welcome.

Thanks,

David