[multisite] Add possibility to hide sites from sidebar (or disable them), if multisite is not used for localization.

[j3ll3yfi5h]

trafficstars

I'm currently using the multisite feature for structuring content after following this conversation: https://discord.com/channels/489818810157891584/489819906540568593/956295170624725112

But it's currently a bit confusing with so many sites in the sidebar and being able to localize them:

It would be handy, if it's possible to disable them or hide them from the sidebar with something like 'localizable' => false,:

    'sites' => [

        'aaa' => [
            'name' => config('app.name'),
            'locale' => 'en_US',
            'url' => '/',
            'localizable' => false,
        ],

        'bbb' => [
            'name' => config('app.name'),
            'locale' => 'en_US',
            'url' => '/',
            'localizable' => false,
        ],

    ],

Any other ideas?

[j3ll3yfi5h]

Collection should be available on all sites, but not localizable... Should it better be a collection setting?

[j3ll3yfi5h]

Related to #17

[godismyjudge95]

Could use this to prevent entries from getting out of hand... When you have 10k+ entries and 4 sites and you don't need localization, it is kind of a waste to create separate entries for each entry for each site.

[finnjsmith]

This feature would be ideal - I have a collection that I want multiple sites to be able to use, but there is no need for the pages created by each site to need to be localised. Having the option to turn this feature off would be great 🙏 I like the idea of having this be an option in the collection configuration, possibly a toggle: "Enable Localisation of Entries" or something similar.