Offer Docs to be downloaded as zip of html files [FEATURE]

[ABDsheikho]

self-explanatory.

I saw that the documentation website offers the docs as pdf file link-for-v20.7, which is something I really like because I work most of the time offline and I relay on reading documentations rather than tutorials.
but as I was scrolling the website, I realized that I'm enjoying the experience and the overall design of it, and I wished it was possible to download the entire documentations as html.zip file.

so why don't you start offering the documentation to be downloaded as zip of html files.

[Poolitzer]

The changes are very simple, we need to add it to the conf file, see https://docs.readthedocs.io/en/stable/downloadable-documentation.html, https://docs.readthedocs.io/en/stable/guides/enable-offline-formats.html, https://docs.readthedocs.io/en/stable/config-file/v2.html#formats.

Downside I see is maybe our download list can get too crowded, but I don't think its that much of an issue.

[kenjitagawa]

I will take this one 😃

[harshil21]

#4079 added this feature, however after downloading the zip file and opening index.html it is not the same as our current site. All classes and modules are on a single page. Not sure what the fix for that can be.

However, as a workaround, I want to point out that our CI uploads the docs build as an artifact and is available for upto 7 days without the above mentioned issue.

[kenjitagawa]

Based on the comment left by one of the maintainers, in issue readthedocs/readthedocs.org#3242, there seems to be a way by adding the post_build job within the build config. The maintainer left an example here, though I haven't gotten around to testing it yet.