Create a how-to on how to test a pre-release version of Django

[Sarah Boyce]

In an episode of DjangoChat, there was a discussion that we need more testers of pre-released Django versions. I am in full agreement that early testers are wonderful and the more the merrier 😊

In order to encourage this, there was a proposal to have a how-to page, as there may be folks who want to do this but don't know how.

We can then link to this in our blog posts when pre-releaes are published.

This how-to probably should link to the ​how-to upgrade Django page, as being on the latest released version is a reasonable prerequisite.

I have also proposed us having a scheduled job to test against djangoproject.com (​https://github.com/django/djangoproject.com/issues/2391) which we may be able to link to in order to give folks an example implementation of testing against Django's main branch.

[Natalia Bidart]

Thank you Sarah for taking the time to create the ticket! I'm in full agreement :-)

[VIZZARD-X]

Hello Parvez, I'm going to assign this to myself since there hasn't been any activity here in a few months and no updates from you regarding the ticket whatsoever.

[VIZZARD-X]

PR: ​https://github.com/django/django/pull/20938
Added the how-to guide for testing pre-releases as requested and verified that the docs successfully build.