Moved book cover image input into collapsible section

Prevent extra friction when creating a new book and makes it easier to
skip if grid view is not in use

resources/assets/js/components/collapsible.js

@@ -0,0 +1,37 @@
+/**
+ * Collapsible
+ * Provides some simple logic to allow collapsible sections.
+ */
+class Collapsible {
+
+    constructor(elem) {
+        this.elem = elem;
+        this.trigger = elem.querySelector('[collapsible-trigger]');
+        this.content = elem.querySelector('[collapsible-content]');
+
+        if (!this.trigger) return;
+
+        this.trigger.addEventListener('click', this.toggle.bind(this));
+    }
+
+    open() {
+        this.elem.classList.add('open');
+        $(this.content).slideDown(400);
+    }
+
+    close() {
+        this.elem.classList.remove('open');
+        $(this.content).slideUp(400);
+    }
+
+    toggle() {
+        if (this.elem.classList.contains('open')) {
+            this.close();
+        } else {
+            this.open();
+        }
+    }
+
+}
+
+module.exports = Collapsible;

resources/assets/js/components/index.js

@@ -15,6 +15,7 @@ let componentMapping = {
     'markdown-editor': require('./markdown-editor'),
     'editor-toolbox': require('./editor-toolbox'),
     'image-picker': require('./image-picker'),
+    'collapsible': require('./collapsible'),
 };
 
 window.components = {};