Migrating image update automation to Flux v2

[valentin-krasontovitsch]

in the section on after flux bootstrap, the docs reference rerunning flux bootstrap with an extra option --components-extra, referring to the installation guide which supposedly shows usage of that extra option. Sadly, that guide has no mention of the option, as far as I could tell.

it's not a big deal, as running flux bootstrap --help outputs

--components-extra strings               list of components in addition to those supplied or defaulted, accepts values such as 'image-reflector-controller,image-automation-controller'

but i thought i'd mention it anyways.