WebAssembly: fix reference to `go install`

Change-Id: I7bfaf2dcdffb5fee2993513d8752f4a36fbfbb1a
Reviewed-on: https://go-review.googlesource.com/c/wiki/+/616955
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
diff --git a/WebAssembly.md b/WebAssembly.md
index f429390..3390766 100644
--- a/WebAssembly.md
+++ b/WebAssembly.md
@@ -92,7 +92,7 @@
 [`goexec`](https://github.com/shurcooL/goexec#goexec):
 
 ```sh
-# install goexec: go install github.com/shurcooL/goexec
+# install goexec: go install github.com/shurcooL/goexec@latest
 goexec 'http.ListenAndServe(`:8080`, http.FileServer(http.Dir(`.`)))'
 ```