update README; add Laravel stubs; add form support

src/Laravel/stubs/action.php

@@ -0,0 +1,44 @@
+<?php
+
+namespace App\Pilot\Actions;
+
+use Bluesquare\Pilot\Entity\Action;
+
+class MakeSmoothie extends Action
+{
+    protected $slug = 'make-smoothie';
+
+    // Optional: you may remove this method if you don't need a form
+    public function form()
+    {
+        return [
+            'flavour' => [
+                'type' => 'text',
+                'label' => 'Flavour',
+                'required' => true,
+            ],
+        ];
+    }
+
+    /**
+     * Available params:
+     * @param $data array The form data
+     * @param $files array The uploaded files
+     * @param $entry mixed|null The Pilot entry ID to execute the action for
+     * @param $entries array<mixed> The Pilot entries ID to execute the action for
+     */
+    public function handle(array $data)
+    {
+        if ($data['flavour'] === 'mayonnaise') {
+            return $this->error('Please choose a better flavour');
+        }
+
+        // ...
+
+        return $this->action(
+            type: 'info',
+            title: 'Smoothie',
+            message: 'Your smoothie is ready!'
+        );
+    }
+}