doc/dev: generate sg ci build command for supported run types

Created by: bobheadxi

Generates documentation for sg ci build [runtype] (https://github.com/sourcegraph/sourcegraph/pull/30932) in the pipeline types reference.

Also updates the sg ci build help text to be a bit more readable (all the available arguments appended was causing some strange line wrapping)

Test plan

sg ci docs
sg run docsite

http://localhost:5080/dev/background-information/ci/reference#main-dry-run