rollup merge of #18696 : tshakah/patch-1

src/doc/guide.md

@@ -1149,7 +1149,7 @@ enum StringResult {
 }
 ```
 Where a `StringResult` is either an `StringOK`, with the result of a computation, or an
-`ErrorReason` with a `String` explaining what caused the computation to fail. This kind of
+`ErrorReason` with a `String` explaining what caused the computation to fail. These kinds of
 `enum`s are actually very useful and are even part of the standard library.
 
 As you can see `enum`s with values are quite a powerful tool for data representation,