Add Topic - AboutJobs

[vexx32]

Describe "Koan(s) You Suggest"

We should add a topic covering Start-Job and Start-ThreadJob (the latter being conditional based on whether the ThreadJob module is installed, or we can add a dependency on the ThreadJob module perhaps?)

Context "The Scope of the Koans You Suggest"

This should cover:

• The behaviour of $using: in these contexts
• The difference between Start-Job and Start-ThreadJob
• Any caveats with using these cmdlets / expectations that may prove to be false (e.g., changes in working directory, variable sharing or not, etc.)
• Various common use cases of these cmdlets