doc: replace tabs with spaces for alignment in code snippets
doc: replace tabs with spaces for alignment in code snippets

Fixes #52255

Change-Id: Ibb518cf2f6bac9e1ffc426a014afe80cc4c0df5e
Reviewed-on: https://go-review.googlesource.com/c/go/+/399394
Reviewed-by: Jamal Carvalho <e0195770807aa8c82b0b128d9c0423b5ad035172@golang.org>
Reviewed-by: Robert Griesemer <a6752097faebf1f02d80107d77a9be009089afe3@google.com>

golang/go,nawawi/go,nawawi/go,golang/go,golang/go,nawawi/go,golang/go,nawawi/go,golang/go,golang/go,nawawi/go,golang/go,nawawi/go,nawawi/go,golang/go,nawawi/go