Support nightly releases

[fabioh8010]

Hi 👋 I'm coming from https://github.com/react-native-community/upgrade-helper/issues/325, I'm planning to implement support for nightly builds in the upgrade-helper tool. After studying the codebase for some time, I saw that it uses this repo to obtain the diffs between the versions.

From what I understood here:

1. When there is a new RN release, you run the new-release.sh script manually (passing the version as a argument) to do all the work of creating the projects to create the diffs, creating a new branch here, updating version tables, etc.
2. upgrade-helper will use RELEASES file to list the versions on the website. Then, when selecting a version, it will fetch the corresponding diff file in the diff branch to display it.

So, first I'll have to add support for nightly releases in this repo in order to add the support in upgrade-helper tool. With that in mind, I have some questions:

1. At the moment, are you still running the script manually? If yes, do you have plans to do this automatically? I don't have much knowledge of GH Actions capabilities, but maybe we could set up an schedule to check for new releases in react-native repo every day?
2. The nightly versions have this version pattern on NPM e.g. 0.73.0-nightly-20230701-eca0d1231, and only the nightly versions of the next release are kept (when a new release is out, the older nightly versions are removed). So, I guess we'll need to take a similar approach here:
   1. When a new stable or RC release is out, remove the old nightly versions from RELEASES file (maybe remove from diffs branch as well?)
3. Does it make sense to add those nightly releases to the HTML table? Personally I think that we shouldn't add, because we are going to have so many entries very quickly (as the nightly builds are generated every day) and it will clutter the list.

Overall, wdyt about this support for nightly builds? Please let me know if you have any questions or feedback!

[fabioh8010]

Hey @pvinis , did you have a chance to take a look at my proposal? Thanks!

[pvinis]

1, it runs automatically. by gh actions if I remember correctly. 3, we def should not add it on the list.

if there point of ain't nighties is to upgrade from a stable to nightly, feels not too useful. I don't know of many people that would do that. most would maybe go to rc, but probably not even there.

if it's to upgrade from a nightly to another nightly, then that's cool but we should hide them behind some settings checkbox to show them or not.

do you think that's useful? what do you think would be it's use?