为 books 添加了折叠和自动折叠

- 添加了一个折叠浮动按钮，可以使 books 折叠起来
- 默认 books 会处于折叠状态，除了在全站主页时会自动展开

Author: Eyre-S

assets/gitbook-fix.css

@@ -27,3 +27,44 @@
 .book .book-summary .exc-trigger:before {
 	content: "\f054";
 }
+
+.book-summary ul.summary div.summary-container {
+	padding: 0;
+	max-height: 0;
+	overflow: hidden;
+}
+
+.book-summary ul.summary div.summary-container.on {
+	padding: 7px 0;
+	max-height: unset;
+}
+
+.book-summary ul.summary li.divider.block-end {
+	margin-top: 0;
+	position: relative;
+	overflow: unset;
+}
+
+.book-summary ul.summary li.divider.block-start {
+	margin-bottom: 0;
+}
+
+.book-summary ul.summary li.divider.block-end .summary-container-icon {
+	position: absolute;
+	top: 1px;
+	right: 20px;
+	padding: 0 5px 2px;
+	background: rgba(0,0,0,.07);
+	color: white;
+	border-bottom: 0;
+	border-radius: 0 0 5px 5px;
+	z-index: 1000;
+}
+
+.book-summary ul.summary li.divider.block-end .summary-container-icon .fa:before {
+	content: "\f078";
+}
+
+.book-summary ul.summary div.summary-container.on + li.divider.block-end {
+	transform: rotateX(180deg);
+}

assets/gitbook-fix.js

@@ -29,3 +29,16 @@ for (let node of document.getElementsByClassName("fold")) {
 		} else node.classList.add("on");
 	});
 }
+
+for (const node of document.getElementsByClassName("summary-container")) {
+	
+	node.nextElementSibling.innerHTML = node.nextElementSibling.innerHTML + "<a class='summary-container-icon'><i class='fa'></i></a>";
+	node.nextElementSibling.getElementsByClassName("summary-container-icon")[0].addEventListener("click", function () {
+		if (node.classList.contains("on")) {
+			node.classList.remove("on")
+		} else {
+			node.classList.add("on")
+		}
+	})
+	
+}

src/Element/Bookshelf.php

@@ -73,9 +73,9 @@ public function getRootBook (): BookContented {
 	public function getHtml (): string {
 		$str = "<ul id='global-container' class='summary'>";
 		$str .= $this->links->getHtml();
-		$str .= "<li class='divider'></li>";
+		$str .= "<li class='divider block-start'></li><div class='summary-container" . (PageMeta::$isMainPage?" on":"") . "'>";
 		$str .= $this->books->getHtml();
-		$str .= "<li class='divider'></li>";
+		$str .= "</div><li class='divider block-end'></li>";
 		$str .= PageMeta::$book->getSummaryHtml();
 		$str .= "<li class='divider'></li><li><a href='https://github.com/Eyre-S/ph-Bookshelf' target='blank' class='gitbook-link'>Generated with ph-Bookshelf</a></li><li><a href='https://www.gitbook.com' target='blank' class='gitbook-link'>Front-End by GitBook</a></li>";
 		$str .= "</ul>";