doc: add a couple of links to go1.11 release notes
doc: add a couple of links to go1.11 release notes

Change-Id: Ie4e81b88cc8035fddf9c074363a1b35bcae3d470
Reviewed-on: https://go-review.googlesource.com/124778
Reviewed-by: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>

cloudflare/go,josharian/go,akutz/go,akutz/go,golang/go,CAFxX/go,josharian/go,nawawi/go,CAFxX/go,CAFxX/go,akutz/go,akutz/go,nawawi/go,golang/go,josharian/go,akutz/go,nawawi/go,cloudflare/go,nawawi/go,josharian/go,nawawi/go,cloudflare/go,cloudflare/go,cloudflare/go,golang/go,nawawi/go,golang/go,golang/go,cloudflare/go,josharian/go,CAFxX/go,akutz/go,akutz/go,akutz/go,cloudflare/go,nawawi/go,josharian/go,CAFxX/go,CAFxX/go,cloudflare/go,CAFxX/go,CAFxX/go,golang/go,nawawi/go,golang/go,golang/go,josharian/go,josharian/go