Merge branch 'hustewart-env-state-doc' into 'master'

Add Environment state definitions

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/143080



Merged-by: Phillip Wells <pwells@gitlab.com>
Approved-by: Vladimir Shushlin <vshushlin@gitlab.com>
Approved-by: Timo Furrer <tfurrer@gitlab.com>
Reviewed-by: Vladimir Shushlin <vshushlin@gitlab.com>
Reviewed-by: Phillip Wells <pwells@gitlab.com>
Reviewed-by: Timo Furrer <tfurrer@gitlab.com>
Co-authored-by: Timo Furrer <tfurrer@gitlab.com>
Co-authored-by: hustewart <hustewart@gitlab.com>