Archive GSOC information on aboutcode RTD home page

[mjherzog]

The home page at https://aboutcode.readthedocs.io/en/latest/ has (apparently) duplicate content in the main TOC for GSoC and GSoD and in the Archived Pages.
We want to keep historical GSoC and GSoD information on this RTD pages for continuity of references to GSoC / GSoD history, but we do not want it on the "home page" because we want to reset the home page as a directory/index for AboutCode project. We use the aboutcode-org wiki to track a current GSoC cycle (https://github.com/aboutcode-org/aboutcode/wiki) so the GSoC/GSoD information here is only for archive/history purposes.

The tasks are to:

• Remove the GSoC and GSoD content from the home page.
• Promote the content under the current AboutCode Project Overview to the home page.

We will then update and expand the list of projects with a separate issue.

[mjherzog]

Also please figure out why we have an error for the Documentation build.

[chinyeungli]

Fixed in https://github.com/aboutcode-org/aboutcode/tree/197_update_RTD