Fix "Edit on GitHub" link

[lgeorge-idm]

Fixed the "Edit on GitHub" link when building on RTD.

• Only override the specific breadcrumbs block instead of the entire side bar
• Changed the edit link to go directly to the web-based GitHub editing interface

Working example: https://docs.idmod.org/projects/covasim/en/rtd_fix-github-edit-link/

[JSchripsema-IDM]

@cliffckerr I think it's a better user experience to point to the RST files, which at least provide a pointer to the correct README that is the source for that HTML topic. Especially as the number of docs files grows, I think going to just the top of the code repo would be frustrating and require digging to find the correct file to edit.

[cliffckerr]

@JSchripsema-IDM I agree that would be preferable, but currently it seems to just point to the index file rather than the actual source file, e.g.: If it could point to the actual source, that would be great, but I'm not sure if it's possible.

[JSchripsema-IDM]

@cliffckerr When I test it, the "Edit on GitHub" link takes me to the correct RST file, which shows that "include:: ../path/to/README" directive. So it's an extra click to get to the correct README file, but at least it tells you where to go. I don't think there's a way to go directly to the README file itself, since the RST file IS what Sphinx is using as the docs source. It copies and pulls in the content of the README file at build time, but the RST file is the source file that Sphinx sees.

[cliffckerr]

@JSchripsema-IDM Ah, OK. For me there's no way to "click" on it, I have to manually edit the URL to go to the right file. But if this is desired behavior, then it's fine with me!