update: resolve release render

docs/.vuepress/components/md/virtual.vue

+<template>
+	<div></div>
+</template>
+
+<script>
+	export default {
+		data() {
+			return {
+				contentFrame: [],
+			};
+		},
+		mounted() {
+			if (this.$isServer) return;
+			const visibleHeight =
+				document.documentElement.clientHeight - document.querySelector('.sub-navbar').clientHeight;
+			const contentRef = document.querySelector('.page .theme-default-content');
+
+			const renderUl = () => {
+				const contentChildren = contentRef.children;
+				[...contentChildren].forEach((child, index) => {
+					if (child.nodeName === 'UL') {
+						const ulHeight = child.clientHeight;
+						const isVisible = visibleHeight + window.scrollY > child.offsetTop - 500;
+						child.style.height = `${ulHeight}px`;
+
+						if (!isVisible) {
+							const _ul = document.createDocumentFragment();
+							[...child.children].forEach(item => _ul.appendChild(item));
+							(!this.contentFrame[index] || !this.contentFrame[index].children.length) &&
+								(this.contentFrame[index] = _ul);
+						} else {
+							if (this.contentFrame[index]) {
+								[...this.contentFrame[index].children].forEach(item => child.appendChild(item));
+							}
+						}
+					}
+				});
+			};
+
+			if (contentRef) {
+				contentRef.style.height = contentRef.clientHeight;
+				renderUl();
+				window.addEventListener('scroll', renderUl);
+			}
+		},
+	};
+</script>

docs/.vuepress/theme/styles/index.styl

 .custom-page-class{
+	position: relative;
 	/* 首页几个logo的排版 */
 	.flex-img-group-view {
 		display flex 

docs/release-note-alpha.md

@@ -2718,3 +2718,5 @@
   + Android平台 修复 创建视频播放控件（VideoPlayer）时，没有开始播放视频也会停止后台背景音频的Bug [详情](https://ask.dcloud.net.cn/question/82034)
   + Android平台 优化 视频播放的操作条的拖动误触和图标美化问题
   + iOS平台 修复 平台绝对路径转换成本地URL路径（plus.io.convertAbsoluteFileSystem）可能返回null的Bug [详情](https://ask.dcloud.net.cn/question/51954)
+
+<md-virtual key="release-note-alpha"/>
\ No newline at end of file

docs/release.md

@@ -3400,3 +3400,5 @@
 * 【重要】新增uni-app，使用vue技术，开发一次，iOS、Android、微信小程序三端同时生成。[详见](https://uniapp.dcloud.io/)
 * 【重要】调整uniapp策略，之前的原生渲染uniapp改为nml项目[详见](https://ask.dcloud.net.cn/article/13507)
 *  uni-app：新增条件编译，采用类似 //#ifdef APP-PLUS 的写法做平台条件编译，代码块名为ifdef，还可双击ifdef选中整体代码段落。[详见](https://uniapp.dcloud.io/platform)
+
+<md-virtual key="release"/>
\ No newline at end of file