content: fix wording on type inference

Fixes golang/go#12517

Change-Id: I63e4940ebef0818ee831bbb4dde81955ea28a1fe
Reviewed-on: https://go-review.googlesource.com/14354
Reviewed-by: Minux Ma <minux@golang.org>
diff --git a/content/basics.article b/content/basics.article
index ae9f47c..b74c63c 100644
--- a/content/basics.article
+++ b/content/basics.article
@@ -182,7 +182,7 @@
 
 * Type inference
 
-When declaring a variable without specifying its type (using `var` without a type or the `:=` syntax), the variable's type is _inferred_ from the value on the right hand side.
+When declaring a variable without specifying an explicit type (either by using the `:=` syntax or `var`=` expression syntax), the variable's type is inferred from the value on the right hand side.
 
 When the right hand side of the declaration is typed, the new variable is of that same type: