Add f4 editor with Go syntax highlighting support Change-Id: I1b38355229fb1c073f706953414501ba83468dcd GitHub-Last-Rev: ac004ef1d20aac4d8e95ddf2da7ecc45f8ad3095 GitHub-Pull-Request: golang/wiki#95 Reviewed-on: https://go-review.googlesource.com/c/wiki/+/766060 Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org> Auto-Submit: Dmitri Shuralyov <dmitshur@golang.org>