Fix a few things in docs

source/docs/v3/upgrading.blade.md

@@ -0,0 +1,72 @@
+---
+title: Upgrading from 2.x
+extends: _layouts.documentation
+section: content
+---
+
+# Upgrading from 2.x
+
+> This hasn't been tested yet and might not be 100% right. It *should* work well, but note the todo at the bottom of the script for updating the `domains` table.
+
+- Move all `_tenancy_` prefixed keys in tenant storage to `tenancy_` prefixed keys
+
+    Run this **with 2.x code** (but put application down first, this will break your app and require that you update to 3.x immediately after). Of course make a backup of the DB first.
+
+    (Note: You may want to make this part of a migration)
+
+    ```php
+    use Stancl\Tenancy\Tenant;
+    tenancy()
+        ->all()
+        ->each(function (Tenant $tenant) {
+            $keys = array_keys($tenant->data);
+            $keys = array_filter($keys, function ($key) {
+                return Str::startsWith($key, '_tenancy_');
+            });
+
+            foreach ($keys as $key) {
+                $value = $tenant->data[$key];
+                unset($tenant->data[$key]);
+                $tenant->data[str_replace('_tenancy_', 'tenancy_', $key)] = $value;
+            }
+
+            $tenant->save();
+        });
+
+    ```
+
+- Add an `id` autoincrement column to `domains` table and retroactively generate the ids
+
+    (Note: You may want to make this part of a migration)
+
+    ```php
+    use Illuminate\Support\Facades\Schema;
+    use Illuminate\Support\Facades\DB;
+    use Illuminate\Database\Schema\Blueprint;
+
+    $domains = DB::table('domains')->get();
+
+    Schema::table('domains', function (Blueprint $table) {
+        $table->unsignedBigInteger('id')->nullable();
+    });
+
+    $counter = 1;
+    foreach ($domains as $domain) {
+        DB::table('domains')
+            ->where('domain', $domain->domain)
+            ->update(['id' => $counter]);
+        $counter += 1;
+    }
+
+    Schema::table('domains', function (Blueprint $table) {
+        $table->dropPrimary();
+    });
+    Schema::table('domains', function (Blueprint $table) {
+        $table->primary('id'); // todo: here we want to make it autoincrement, not just primary
+    });
+    ```
+
+- Replace your Http Kernel with a stock version (copy it from laravel/laravel: [https://github.com/laravel/laravel/blob/master/app/Http/Kernel.php](https://github.com/laravel/laravel/blob/master/app/Http/Kernel.php)) and add back in any changes you made. The package now doesn't necessitate any Kernel changes, so remove all of the 2.x ones.
+- Delete config, publish it & the new files using `php artisan tenancy:install`
+- Create Tenant model, as instructed on the [Tenants]({{ $page->link('tenants') }}) page
+- Update routes to use the correct middleware, see the [Routes]({{ $page->link('routes') }}) page