doc: fix spelling mistake
doc: fix spelling mistake

Change-Id: I7bf1a93d3377acccdd3a34c5dcef7863310496e0
Reviewed-on: https://go-review.googlesource.com/89955
Reviewed-by: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@golang.org>

nawawi/go,CAFxX/go,CAFxX/go,Cofyc/go,josharian/go,akutz/go,Cofyc/go,josharian/go,josharian/go,Cofyc/go,josharian/go,cloudflare/go,akutz/go,josharian/go,cloudflare/go,cloudflare/go,josharian/go,golang/go,codestation/go,Cofyc/go,akutz/go,golang/go,golang/go,codestation/go,golang/go,cloudflare/go,golang/go,Cofyc/go,nawawi/go,akutz/go,nawawi/go,codestation/go,akutz/go,codestation/go,nawawi/go,nawawi/go,akutz/go,nawawi/go,CAFxX/go,akutz/go,CAFxX/go,codestation/go,CAFxX/go,akutz/go,cloudflare/go,christopher-henderson/Go,codestation/go,nawawi/go,codestation/go,cloudflare/go,josharian/go,cloudflare/go,CAFxX/go,codestation/go,cloudflare/go,golang/go,golang/go,Cofyc/go,josharian/go,Cofyc/go,golang/go,CAFxX/go,nawawi/go,CAFxX/go,Cofyc/go