docs(lib/mediawiki): initial documentation writeup

docs/src/content/docs/contributing/mediawiki-library.md

@@ -0,0 +1,32 @@
+---
+title: MediaWiki Library
+description: Reference to using the MediaWiki library.
+---
+
+The MediaWiki library is a collection of mixins to consistently theme userstyles targeting the Vector 2022 MediaWiki skin. 
+
+[Source code](https://github.com/catppuccin/userstyles/blob/main/lib/mediawiki.less)
+
+See the [Library Modules](/contributing/library-modules/) article for information on what libraries are and what problems they solve.
+
+# Usage
+
+Add the import block at the top of the userstyle:  
+```less  
+@import "https://userstyles.catppuccin.com/lib/mediawiki.less";  
+```  
+Outside the `#catppuccin` mixin, add the reset block to \<add explanation\>
+
+```less  
+#__mediawiki.reset();  
+```
+
+Then, inside the `#catppuccin` mixin, add the base block to add CSS variables and other styles.  
+
+```less
+\#\_\_mediawiki.base();  
+```
+
+# API
+
+TO-DO