Added Sites to engine.py

[austinsonger]

No description provided.

[GoodluckH]

thanks for contributing to our lowkey repo lol. we really appreciate all contributions. for now we are focusing on software engineer positions only so the compliance comprehensive query might not be needed but might be able to keep the rest of the changes.

also, for each newly added job board, helper functions are needed to extract information (see get_lever_job_details as an example).