doc: update go1.11 release notes
doc: update go1.11 release notes

Update text/scanner and text/template sections.

Change-Id: I1a273e99ff400870053cca63cea68fb7a9b56764
Reviewed-on: https://go-review.googlesource.com/124705
Reviewed-by: Andrew Bonventre <682ad9f487f614f19e8b7cc5d340bdc8e1c1b128@golang.org>

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