_content/doc: fix a broken link to Querying topic
_content/doc: fix a broken link to Querying topic

This change fixes a link from /doc/database/change-data
to /doc/database/querying.

Change-Id: I76b57d0df17b4ef65dc02afd0a1f33aeef262243
Reviewed-on: https://go-review.googlesource.com/c/website/+/332251
Reviewed-by: Russ Cox <5ad239cb8a44f659eaaee0aa1ea5b94947abe557@golang.org>
Trust: Steve Traut <af4cad49c6f706d4616eefecc2c596e86c262fed@google.com>

golang/website,golang/website,golang/website,golang/website,golang/website,golang/website,golang/website