feat(sidebar): 处理一个 tab 为两个空格

docs/.vuepress/markdown/createSidebar.js

@@ -13,7 +13,7 @@ function parseBar(tab, file, options) {
 	const linkName = options.link || 'link'
 	const contents = []
 
-	new MarkdownIt().parse(fs.readFileSync(file, { encoding: 'utf-8' }).replace(/<!--([\s\S]*?)-->/g, '')).forEach(token => {
+	new MarkdownIt().parse(fs.readFileSync(file, { encoding: 'utf-8' }).replace(/<!--([\s\S]*?)-->/g, '').replace(/\t/g, '  ')).forEach(token => {
 		if (token.type === 'inline') {
 			let text
 			let link