Documentation for generic live command support

[Martin-Molinero]

Expected Behavior

• Documentation for new generic live command support. See Generic live command support Lean#8330 & Add generic live command support lean-cli#501

Actual Behavior

N/A

Checklist

• I have completely filled out this template
• I have confirmed that this issue exists on the current master branch
• I have confirmed that this is not a duplicate issue by searching issues

[Martin-Molinero]

See QuantConnect/Lean#8348, adding Link support

[AlexCatarino]

See Live Trading > Commands.