spec: fix inconsistency of visibility rules for method names

Inconsistency identified by Anmol Sethi (anmol@aubble.com).

Fixes #10341.

Change-Id: I1a1f5b22aad29b56280f81026feaa37a61b3e0a9
Reviewed-on: https://go-review.googlesource.com/13132Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

doc/go_spec.html

@@ -2097,7 +2097,8 @@ parentheses) where <code>T</code> is a type name. The type denoted by <code>T</c
 the receiver <i>base type</i>; it must not be a pointer or interface type and
 it must be declared in the same package as the method.
 The method is said to be <i>bound</i> to the base type and the method name
-is visible only within selectors for that type.
+is visible only within <a href="#Selectors">selectors</a> for type <code>T</code>
+or <code>*T</code>.
 </p>
 
 <p>