[release-branch.r59] doc: document release.r59

««« CL 4835044 / d655c911a608
doc: document release.r59

R=golang-dev, dsymonds, r, r
CC=golang-dev
https://golang.org/cl/4835044
»»»

R=r
CC=golang-dev
https://golang.org/cl/4801068
2 files changed