Add the XML plugin to the docs (#6944)

docs/plugins.md

@@ -45,6 +45,7 @@ Providing at least one path to `--plugin-search-dir`/`pluginSearchDirs` turns of
 - [`@prettier/plugin-pug`](https://github.com/prettier/plugin-pug) by [**@Shinigami92**](https://github.com/Shinigami92)
 - [`@prettier/plugin-ruby`](https://github.com/prettier/plugin-ruby)
 - [`@prettier/plugin-swift`](https://github.com/prettier/plugin-swift)
+- [`@prettier/plugin-xml`](https://github.com/prettier/plugin-xml)
 
 ## Community Plugins
 

website/data/languages.yml

@@ -49,3 +49,4 @@
   - "[Ruby](https://github.com/prettier/plugin-ruby)"
   - "[Swift](https://github.com/prettier/plugin-swift)"
   - "[TOML](https://github.com/bd82/toml-tools/tree/master/packages/prettier-plugin-toml)"
+  - "[XML](https://github.com/prettier/plugin-xml)"