Update documentation for Thunderbird + calendars + contacts

Tbsync's caldav/carddav backend is no longer compatible with recent
versions of Thunderbird and so this method doesn't work anymore.

service/nextcloud.md

@@ -303,21 +303,58 @@ Note: the above instructions come from [this tutorial](https://narrira.medium.co
 
 ### Mac, Windows, Linux: Thunderbird
 
-[Thunderbird](https://www.thunderbird.net), made by the [Mozilla foundation](https://mozilla.org), has a [built-in calendar](https://www.thunderbird.net/en-US/calendar/). This used to be a separate extension called Lightning, but it is now integrated into Thunderbird itself.
-
-It's a good choice if you already use Thunderbird, but you can also use it as a calendar if you do not use Thunderbird.
-
-In order to use the calendar, you need to first generate an App password, and then install a couple of add-ons. 
-
-First create a Nextcloud "App" password by logging into the Nextcloud web interface, and then go to your profile->Settings->Security->Create a new App Password. Give it a name and then copy the randomly generated password (you cannot see the password again after you are finished!), then click Done. Note: if you did this previously for Android, its not a bad idea to have a separate App Password for Thunderbird, that way you can revoke the Android password, if you lose your device, and still have access to your Thunderbird calendar.
-
-Simply go to Tools->Addons and Themes->Search->`Tbsync` install. Then in the `Tbsync` preferences -> Account Actions -> Add new account -> CalDAV & CardDAV -> install the plugin for this connector.
-
-Then under the `Tbsync` preferences, you pick "Account actions" in the lower left, then "Add new account" -> "CalDAV & CardDAV". Then pick "Automatic Configuration". Put an account name (your choice), your Nextcloud username, your App Password you generated previously and then for Server URL, just put "nc.torproject.org" and click "Next".
-
-Now just select the calendars you wish to synchronize and click "Synchronize now", and you should be all set.
-
-If you have trouble finding the calendar in Thunderbird, it can be a little bit hidden. Just look for the little icon in the upper right that says "Switch to the calendar tab" when you hover over it.
+[Thunderbird](https://www.thunderbird.net), made by the [Mozilla
+foundation](https://mozilla.org), has a [built-in
+calendar](https://www.thunderbird.net/en-US/calendar/). This used to be a
+separate extension called Lightning, but it is now integrated into Thunderbird
+itself. Thunderbird also integrated builtin support for CalDAV/CardDAV from
+version 120 onwards.
+
+It's a good choice if you already use Thunderbird, but you can also use it as a
+calendar if you do not use Thunderbird.
+
+In order to use the calendar, you need to first generate an App password. Then
+you'll ask Thunderbird to find your calendars.
+
+Nextcloud "App" password:
+
+Log into the Nextcloud web interface, and then go to your
+profile->Settings->Security->Create a new App Password (at the very bottom of
+the page). Give it a name and then copy the randomly generated password (you
+cannot see the password again after you are finished!), then click Done.
+
+Note: if you did this previously for Android, it's not a bad idea to have a
+separate App Password for Thunderbird. That way you can revoke the Android
+password if you lose your device and still have access to your Thunderbird
+calendar.
+
+Calendars:
+
+Open up the calendar view in Thunderbird (in versions 120+ it's the calendar
+icon on the left vertical bar). Click on "New Calendar" and select "On the
+Network". Then ender the user name associated to your app password and for the
+URL use the following: https://nc.torproject.net/remote.php/dav
+
+After hitting the "Next" button, you'll be prompted for your app password.
+Normally after a little while you should be able to subscribe to your calendars
+(including the ones shared with you by other users).
+
+Note: Nextcloud used to recommend using the `Tbsync` plugin with its associated
+CalDAV/CardDAV backend plugin, but this does not work anymore for Thunderbird
+120+. If you're still using an older version, refer to [Nextcloud's
+documentation](https://docs.nextcloud.com/server/latest/user_manual/en/groupware/sync_thunderbird.html#alternative-using-the-tbsync-addon)
+to setup Tbsync.
+
+Contacts:
+
+To automatically get all of your contacts from nextcloud, open the Address Book
+view (in the left vertical bar in versions 120+). Click on the arrow beside
+"New Address Book" and choose "Add CardDav Address Book". Then enter the
+username associated to your app password and for the URL, use the same URL as
+for the calendars: https://nc.torproject.net/remote.php/dav
+
+After hitting "Next" you'll be prompted for your app password and after a while
+you should be able to choose from the sources of contacts to synchronize from.
 
 ### Linux: GNOME Calendar, KDE Korganizer