How to customize pre-chat survey with input parameters sample

[momahm311]

Is your feature request related to a problem? Please describe.
Missing sample for how to pass values (input) from custom pre-chat survey adaptive card to context variables

Describe the solution you'd like
Update docs with sample on how to set Ids when overriding the OOB pre-chat survey adaptive card with LCW 2.0

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context
Add any other context or screenshots about the feature request here.