Add endpoint for suggested instance (fixes #581)

[Nutomic]

No description provided.

[Nutomic]

It seems like these two libraries are breaking the build: https://woodpecker.join-lemmy.org/repos/128/pipeline/1886/7

[Nutomic]

This has some overlap with the routes for api documentation.

[dessalines]

To me adding all the IP and geo stuff seems way overkill. Just serialize the suggested instances and ignore all the IP / location considerations.

[Nutomic]

We need that to find out which country the current user IP belongs to. How else do you propose to match the user and instance locations?

[dessalines]

Its up to you I spose, but really I'd rather this endpoint serialize all the recommended instances (including the suggested flag I added).

To me the main use case of this endpoint, is so that apps don't have to hardcode a large list of instances in their dropdown for choosing an instance inside their app. The instances_metadata list contains all the info that join-lemmy uses, that apps could also use to create their own in-app instance pickers / dropdowns / list.

[Nutomic]

That can be a separate endpoint. Normally users shouldnt have to choose an instance manually at all, and simply use the suggested one. The signup UI I'm thinking about would look like this:

Register on example.com
Username: ...
Password: ...
Other inputs
Register | Browse all instances

Edit: Added endpoint /api/v1/instances/all. Cant test it yet due to the error from package.json.