Improve Importing Data / Streaming / CSV Examples

Inline the examples like the other pages so doesn't require linking out.
Show usage of multiple properties. 
https://www.quantconnect.com/docs/v2/writing-algorithms/importing-data/streaming-data/custom-securities/csv-format-example

https://www.quantconnect.cloud/backtest/8f24cfcf1e480923d34446501dd37d9f/?theme=chrome