tour: correct typo

Change-Id: I14f0317c1f6c36aa922c43eab45a7bc4dd698142
Reviewed-on: https://go-review.googlesource.com/c/website/+/394314
Reviewed-by: Eli Bendersky‎ <eliben@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Run-TryBot: Eli Bendersky‎ <eliben@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Trust: Eli Bendersky <eliben@google.com>
diff --git a/_content/tour/generics.article b/_content/tour/generics.article
index 4d6f97e..5da258d 100644
--- a/_content/tour/generics.article
+++ b/_content/tour/generics.article
@@ -25,7 +25,7 @@
 * Generic types
 
 In addition to generic functions, Go also supports generic types. A type can
-be parameterized with a type paremeter, which could be useful for implementing
+be parameterized with a type parameter, which could be useful for implementing
 generic data structures.
 
 This example demonstrates a simple type declaration for a singly-linked list