strings: add Examples for TrimFunc and variants during Gophercon!
strings: add Examples for TrimFunc and variants during Gophercon!

Change-Id: I6bfe5b914cf11be1cd1f8e61d557cc718725f0be
Reviewed-on: https://go-review.googlesource.com/49013
Run-TryBot: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@golang.org>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@golang.org>

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