Merge commit '9b0050e9aabe4be65c78ccf292a348f309d50ccd' as 'docs'

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

Closes #11925

docs/content/en/functions/collections/SymDiff.md

@@ -0,0 +1,24 @@
+---
+title: collections.SymDiff
+description: Returns the symmetric difference of two collections.
+categories: []
+keywords: []
+action:
+  aliases: [symdiff]
+  related:
+    - functions/collections/Complement
+    - functions/collections/Intersect
+    - functions/collections/SymDiff
+    - functions/collections/Union
+  returnType: any
+  signatures: [COLLECTION | collections.SymDiff COLLECTION]
+aliases: [/functions/symdiff]
+---
+
+Example:
+
+```go-html-template
+{{ slice 1 2 3 | symdiff (slice 3 4) }} → [1 2 4]
+```
+
+Also see <https://en.wikipedia.org/wiki/Symmetric_difference>.