Docs: Add more information about staging CI/CD

[clavery]

specifically certificate 2fa requirements
add to CI/CD, migration, related pages

[nilay-macwan]

Hi @clavery Do you have any estimated timeline for when the doc will be updated with staging CI/CD information ?

[clavery]

hi @nilay-macwan just added to the top of my list for the next docs pass. Thanks for reminding me