text/template: more godoc links

Change-Id: I4f3684ea6cbdcc09985c93fef5107d3bd006699e
Reviewed-on: https://go-review.googlesource.com/c/go/+/544735
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>

src/text/template/doc.go

@@ -438,13 +438,13 @@ produce the text
 By construction, a template may reside in only one association. If it's
 necessary to have a template addressable from multiple associations, the
 template definition must be parsed multiple times to create distinct *Template
-values, or must be copied with the Clone or AddParseTree method.
+values, or must be copied with [Template.Clone] or [Template.AddParseTree].
 
 Parse may be called multiple times to assemble the various associated templates;
-see the ParseFiles and ParseGlob functions and methods for simple ways to parse
-related templates stored in files.
+see [ParseFiles], [ParseGlob], [Template.ParseFiles] and [Template.ParseGlob]
+for simple ways to parse related templates stored in files.
 
-A template may be executed directly or through ExecuteTemplate, which executes
+A template may be executed directly or through [Template.ExecuteTemplate], which executes
 an associated template identified by name. To invoke our example above, we
 might write,