Merge commit '9b0050e9aabe4be65c78ccf292a348f309d50ccd' as 'docs'

```
git subtree add --prefix=docs/ https://github.com/gohugoio/hugoDocs.git master --squash
```

Closes #11925

docs/content/en/functions/resources/Concat.md

@@ -0,0 +1,26 @@
+---
+title: resources.Concat
+description: Returns a concatenated slice of resources.
+categories: []
+keywords: []
+action:
+  aliases: []
+  related: []
+  returnType: resource.Resource
+  signatures: ['resources.Concat TARGETPATH [RESOURCE...]']
+---
+
+The `resources.Concat` function returns a concatenated slice of resources, caching the result using the target path as its cache key. Each resource must have the same [media type].
+
+Hugo publishes the resource to the target path when you call its [`Publish`], [`Permalink`], or [`RelPermalink`] methods. 
+
+[media type]: https://en.wikipedia.org/wiki/Media_type
+[`publish`]: /methods/resource/publish
+[`permalink`]: /methods/resource/permalink
+[`relpermalink`]: /methods/resource/relpermalink
+
+```go-html-template
+{{ $plugins := resources.Get "js/plugins.js" }}
+{{ $global := resources.Get "js/global.js" }}
+{{ $js := slice $plugins $global | resources.Concat "js/bundle.js" }}
+```