language/display: fix Tag method comment
language/display: fix Tag method comment

Minor fix to comment.

Change-Id: I181de709f02faf433e97f38208039bf789e6b71d
GitHub-Last-Rev: fd7f6501c5c677ba7f1d6779bb88cbf82c9a6f10
GitHub-Pull-Request: golang/text#19
Reviewed-on: https://go-review.googlesource.com/c/text/+/293469
Reviewed-by: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@google.com>
Reviewed-by: Marcel van Lohuizen <a22d082192f3ccf984644a4f482781f4c2d65180@golang.org>
Run-TryBot: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@google.com>
Auto-Submit: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@google.com>
Run-TryBot: Marcel van Lohuizen <a22d082192f3ccf984644a4f482781f4c2d65180@golang.org>
Reviewed-by: Carlos Amedee <ab5e2bca84933118bbc9d48ffaccce3bac4eeb64@golang.org>
TryBot-Result: Gopher Robot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>

golang/text