Update sarotate.md

[RaneyDazed]

Updated sarotate.md page, added to mkdocs, added brief explanation for service account actions.

• [x] App documentation page updated
• [x] Reference added in mkdocs.yml

[RaneyDazed]

Whomever takes a look at it, lmk if I should move the SA example before sb install sandbox-sarotate or if its fine?

[maximuskowalski]

Not sure if it might be worth filling some details in as an example in the rest of the config file.

[RaneyDazed]

I'll try to get back to this today at some point. :)

[RaneyDazed]

I guess I’ll need to get back to this huh? 😂 people are asking questions!