Adjust TOC for https://aboutcode.readthedocs.io

[mjherzog]

We currently have the GSoC projects hidden under: https://aboutcode.readthedocs.io/en/latest/archive.html#table-of-contents.
Please move GSoC to the TOC top level after Contributing to AboutCode. It is not intuitive to look for these under Archived Pages.

At some point we will want to also promote GSoD, but we can leave it and Contributor Project Ideas (old) under the Archived Pages for now. We should remove the TOC level under Archived Pages if that is easy to do.
It would be nice to make the change quickly so that we can post the better link with the News item for completing GSoC 2022 on aboutcode.org.

[AyanSinhaMahapatra]

@mjherzog see https://aboutcode-test.readthedocs.io/en/restructure-gsoc-pages/ for docs, is this okay now?

Note that we can't change the URL as these are displayed in gsoc website and are the submission links, but I modified the front page to display GSoC infor directly.

[mjherzog]

@AyanSinhaMahapatra I understand the point. The updated layout looks good.