Distributed computing page not present in TOC

[mbsabath]

The distributed computing page isn't present in the TOC, seems like it was removed during a recent update. It should be readded to the TOC to it's available to share with users

[ebatty]

We will get back to this after restructuring the handbook table of contents to see best placement of different components @mbsabath

[SarahL88]

@Naeemkh, since you are restructuring the Handbook, please either assign this issue to yourself, or delete the issue, per your preference.