docs: fix typo, fixed #114

Author: QingWei-Li

docs/_sidebar.md

@@ -10,7 +10,7 @@
   - [List of Plugins](/plugins)
   - [Write a Plugin](/write-a-plugin)
   - [Markdown configuration](/markdown)
-  - [Lanuage highlighting](/language-highlight)
+  - [Language highlighting](/language-highlight)
 
 - Guide
  - [Deploy](/deploy)

docs/custom-navbar.md

@@ -61,7 +61,7 @@ You can create sub-lists by indenting items that are under a certain parent.
   - [Themes](/themes)
   - [Using plugins](/plugins)
   - [Markdown configuration](/markdown)
-  - [Lanuage highlight](/language-highlight)
+  - [Language highlight](/language-highlight)
 ```
 
 renders as