docs(en,zh): update for language label & language alias features

docs/en/guide/markdown.md

@@ -365,7 +365,7 @@ export default {
 
 A [list of valid languages](https://shiki.style/languages) is available on Shiki's repository.
 
-You may also customize syntax highlight theme in app config. Please see [`markdown` options](../reference/site-config#markdown) for more details.
+You may also customize syntax highlight theme, configure language aliases, and set custom language labels in app config. Please see [`markdown` options](../reference/site-config#markdown) for more details.
 
 ## Line Highlighting in Code Blocks
 

docs/zh/guide/markdown.md

@@ -343,7 +343,7 @@ export default {
 
 在 Shiki 的代码仓库中，可以找到[合法的编程语言列表](https://shiki.style/languages)。
 
-还可以全局配置中自定义语法高亮主题。有关详细信息，参见 [`markdown` 选项](../reference/site-config#markdown)得到更多信息。
+还可以在全局配置中自定义语法高亮主题、配置语言别名和自定义语言标签。有关详细信息，参见 [`markdown` 选项](../reference/site-config#markdown)得到更多信息。
 
 ## 在代码块中实现行高亮 {#line-highlighting-in-code-blocks}